[BUG] Incompatibility with 3.12-style generics (PEP695)

[zacharyrs]

Describe the bug

Using PEP695 type parameters syntax conflicts with TensorClass's bracket-based configuration.

To Reproduce

from tensordict import TensorClass
class A[T: int](TensorClass):
    a: int
    def do_thing(self, t: T) -> None:
        ...
        
class B[T: int](A[T]):
    ...
     
Traceback (most recent call last):
  File "<python-input-29>", line 1, in <module>
    class B[T: int](A[T]):
        ...
  File "<python-input-29>", line 1, in <generic parameters of B>
    class B[T: int](A[T]):
                    ~^^^
  File "/Users/.../python3.13/site-packages/tensordict/tensorclass.py", line 3072, in __getitem__
    name = "_".join(item)  # type: ignore
TypeError: sequence item 0: expected str instance, typing.TypeVar found```

Similarly...

class B(A[int]):
    ...
    
Traceback (most recent call last):
  File "<python-input-30>", line 1, in <module>
    class B(A[int]):
            ~^^^^^
  File "/Users/.../python3.13/site-packages/tensordict/tensorclass.py", line 3072, in __getitem__
    name = "_".join(item)  # type: ignore
TypeError: sequence item 0: expected str instance, type found

And finally...

class B(A["int"]):
    ...

Traceback (most recent call last):
  File "<python-input-31>", line 1, in <module>
    class B(A["int"]):
            ~^^^^^^^
  File "/Users/.../python3.13/site-packages/tensordict/tensorclass.py", line 3077, in __getitem__
    result = _TensorClassMeta(  # type: ignore
        cls_name,
    ...<2 lines>...
        **{_item: True for _item in item},
    )
  File "/Users/.../python3.13/site-packages/tensordict/tensorclass.py", line 3032, in __new__
    cls = super().__new__(mcs, name, bases, namespace, **kwargs)
  File "<frozen abc>", line 106, in __new__
  File "/Users/.../cpython-3.13.1-macos-aarch64-none/lib/python3.13/typing.py", line 1257, in _generic_init_subclass
    super(Generic, cls).__init_subclass__(*args, **kwargs)
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^
TypeError: TensorClass_int.__init_subclass__() takes no keyword arguments

Expected behavior

Generics to have priority.

System info

Describe the characteristic of your environment:

• pip; uv venv
• 3.13.1

import tensordict, numpy, sys, torch
print(tensordict.__version__, numpy.__version__, sys.version, sys.platform, torch.__version__)
0.10.0 2.1.3 3.13.1 (main, Jan  5 2025, 06:22:40) [Clang 19.1.6 ] darwin 2.8.0

Reason and Possible fixes

tensordict/tensordict/tensorclass.py

Line 3086 in 3e856cb

def __getitem__(cls, item: IndexType) -> Self:

Checklist

• I have checked that there is no similar issue in the repo (required)
• I have read the documentation (required)
• I have provided a minimal working example to reproduce the bug (required)

[zacharyrs]

For now I'm just getting rid of those!

from tensordict import TensorClass
from tensordict.tensorclass import _TensorClassMeta

del _TensorClassMeta.__getitem__
del TensorClass.__class_getitem__