[glass] Fix compilation errors from C++23 Clang

[calcmogul]

In file included from /Users/runner/work/allwpilib/allwpilib/glass/src/libnt/native/cpp/NTMechanism2D.cpp:5:
In file included from /Users/runner/work/allwpilib/allwpilib/glass/src/libnt/native/include/glass/networktables/NTMechanism2D.h:7:
In file included from /Applications/Xcode_15.4.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX14.5.sdk/usr/include/c++/v1/memory:898:
In file included from /Applications/Xcode_15.4.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX14.5.sdk/usr/include/c++/v1/__memory/shared_ptr.h:31:
/Applications/Xcode_15.4.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX14.5.sdk/usr/include/c++/v1/__memory/unique_ptr.h:66:19: error: invalid application of 'sizeof' to an incomplete type '(anonymous namespace)::NTMechanismObjectModel'
    static_assert(sizeof(_Tp) >= 0, "cannot delete an incomplete type");
                  ^~~~~~~~~~~
/Applications/Xcode_15.4.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX14.5.sdk/usr/include/c++/v1/__memory/unique_ptr.h:300:7: note: in instantiation of member function 'std::default_delete<(anonymous namespace)::NTMechanismObjectModel>::operator()' requested here
      __ptr_.second()(__tmp);
      ^
/Applications/Xcode_15.4.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX14.5.sdk/usr/include/c++/v1/__memory/unique_ptr.h:266:75: note: in instantiation of member function 'std::unique_ptr<(anonymous namespace)::NTMechanismObjectModel>::reset' requested here
  _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_SINCE_CXX23 ~unique_ptr() { reset(); }
                                                                          ^
/Applications/Xcode_15.4.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX14.5.sdk/usr/include/c++/v1/__memory/construct_at.h:69:13: note: in instantiation of member function 'std::unique_ptr<(anonymous namespace)::NTMechanismObjectModel>::~unique_ptr' requested here
    __loc->~_Tp();
            ^
/Applications/Xcode_15.4.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX14.5.sdk/usr/include/c++/v1/__memory/construct_at.h:104:10: note: in instantiation of function template specialization 'std::__destroy_at<std::unique_ptr<(anonymous namespace)::NTMechanismObjectModel>, 0>' requested here
    std::__destroy_at(__loc);
         ^
/Applications/Xcode_15.4.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX14.5.sdk/usr/include/c++/v1/__memory/allocator_traits.h:323:16: note: in instantiation of function template specialization 'std::destroy_at<std::unique_ptr<(anonymous namespace)::NTMechanismObjectModel>, 0>' requested here
        _VSTD::destroy_at(__p);
               ^
/Applications/Xcode_15.4.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX14.5.sdk/usr/include/c++/v1/vector:944:25: note: in instantiation of function template specialization 'std::allocator_traits<std::allocator<std::unique_ptr<(anonymous namespace)::NTMechanismObjectModel>>>::destroy<std::unique_ptr<(anonymous namespace)::NTMechanismObjectModel>, void, void>' requested here
        __alloc_traits::destroy(__alloc(), std::__to_address(--__soon_to_be_end));
                        ^
/Applications/Xcode_15.4.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX14.5.sdk/usr/include/c++/v1/vector:938:29: note: in instantiation of member function 'std::vector<std::unique_ptr<(anonymous namespace)::NTMechanismObjectModel>>::__base_destruct_at_end' requested here
  void __clear() _NOEXCEPT {__base_destruct_at_end(this->__begin_);}
                            ^
/Applications/Xcode_15.4.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX14.5.sdk/usr/include/c++/v1/vector:489:20: note: in instantiation of member function 'std::vector<std::unique_ptr<(anonymous namespace)::NTMechanismObjectModel>>::__clear' requested here
            __vec_.__clear();
                   ^
/Applications/Xcode_15.4.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX14.5.sdk/usr/include/c++/v1/vector:500:67: note: in instantiation of member function 'std::vector<std::unique_ptr<(anonymous namespace)::NTMechanismObjectModel>>::__destroy_vector::operator()' requested here
  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI ~vector() { __destroy_vector(*this)(); }
                                                                  ^
/Users/runner/work/allwpilib/allwpilib/glass/src/libnt/native/cpp/NTMechanism2D.cpp:39:3: note: in instantiation of member function 'std::vector<std::unique_ptr<(anonymous namespace)::NTMechanismObjectModel>>::~vector' requested here
  NTMechanismGroupImpl(nt::NetworkTableInstance inst, std::string_view path,
  ^
/Users/runner/work/allwpilib/allwpilib/glass/src/libnt/native/cpp/NTMechanism2D.cpp:35:7: note: forward declaration of '(anonymous namespace)::NTMechanismObjectModel'
class NTMechanismObjectModel;
      ^

Explicitly declaring NTMechanismObjectModel's destructor fixes this specific error, but I get errors for RootModel from other .cpp files like StandardNetworkTables.cpp as well.

In file included from /home/tav/frc/wpilib/allwpilib/glass/src/libnt/native/cpp/StandardNetworkTables.cpp:5:
In file included from /usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/15.1.1/../../../../include/c++/15.1.1/memory:80:
/usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/15.1.1/../../../../include/c++/15.1.1/bits/unique_ptr.h:91:16: error: invalid application of 'sizeof' to an incomplete type 'glass::NTMechanism2DModel::RootModel'
   91 |         static_assert(sizeof(_Tp)>0,
      |                       ^~~~~~~~~~~
/usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/15.1.1/../../../../include/c++/15.1.1/bits/unique_ptr.h:399:4: note: in instantiation of member function 'std::default_delete<glass::NTMechanism2DModel::RootModel>::operator()' requested here
  399 |           get_deleter()(std::move(__ptr));
      |           ^
/usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/15.1.1/../../../../include/c++/15.1.1/bits/stl_construct.h:88:15: note: in instantiation of member function 'std::unique_ptr<glass::NTMechanism2DModel::RootModel>::~unique_ptr' requested here
   88 |         __location->~_Tp();
      |                      ^
/usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/15.1.1/../../../../include/c++/15.1.1/bits/stl_construct.h:164:12: note: in instantiation of function template specialization 'std::destroy_at<std::unique_ptr<glass::NTMechanism2DModel::RootModel>>' requested here
  164 |       std::destroy_at(__pointer);
      |            ^
/usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/15.1.1/../../../../include/c++/15.1.1/bits/stl_construct.h:212:9: note: in instantiation of function template specialization 'std::_Destroy<std::unique_ptr<glass::NTMechanism2DModel::RootModel>>' requested here
  212 |           std::_Destroy(std::__addressof(*__first));
      |                ^
/usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/15.1.1/../../../../include/c++/15.1.1/bits/alloc_traits.h:1045:12: note: in instantiation of function template specialization 'std::_Destroy<std::unique_ptr<glass::NTMechanism2DModel::RootModel> *>' requested here
 1045 |       std::_Destroy(__first, __last);
      |            ^
/usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/15.1.1/../../../../include/c++/15.1.1/bits/stl_vector.h:802:7: note: in instantiation of function template specialization 'std::_Destroy<std::unique_ptr<glass::NTMechanism2DModel::RootModel> *, std::unique_ptr<glass::NTMechanism2DModel::RootModel>>' requested here
  802 |         std::_Destroy(this->_M_impl._M_start, this->_M_impl._M_finish,
      |              ^
/home/tav/frc/wpilib/allwpilib/glass/src/libnt/native/include/glass/networktables/NTMechanism2D.h:29:3: note: in instantiation of member function 'std::vector<std::unique_ptr<glass::NTMechanism2DModel::RootModel>>::~vector' requested here
   29 |   ~NTMechanism2DModel() override {}
      |   ^
/home/tav/frc/wpilib/allwpilib/glass/src/libnt/native/include/glass/networktables/NTMechanism2D.h:58:9: note: forward declaration of 'glass::NTMechanism2DModel::RootModel'
   58 |   class RootModel;
      |         ^