Require nanobind>=2.5.0

[francesco-ballarin]

Needed due to #3617. Otherwise the user may get odd errors like

#23 127.3       CMake Error at /usr/local/lib/python3.12/site-packages/nanobind/cmake/nanobind-config.cmake:316 (add_library):
#23 127.3         Cannot find source file:
#23 127.3       
#23 127.3           NB_SUPPRESS_WARNINGS
#23 127.3       Call Stack (most recent call first):
#23 127.3         CMakeLists.txt:34 (nanobind_add_module)
#23 127.3       
#23 127.3       
#23 127.3       CMake Error at /usr/local/lib/python3.12/site-packages/nanobind/cmake/nanobind-config.cmake:316 (add_library):
#23 127.3         No SOURCES given to target: cpp
#23 127.3       Call Stack (most recent call first):
#23 127.3         CMakeLists.txt:34 (nanobind_add_module)
#23 127.3       
#23 127.3       
#23 127.3       CMake Generate step failed.  Build files cannot be regenerated correctly.