bindings: allow use of `pathlib.Path | str` for paths

[nim65s]

Hi,

This update the python bindings to allow passing filenames through pathlib objects, without breaking compatibility with the previous way of passing filenames through bare str.

It also modernize python code by adding the PTH ruff check and update os.path code with pathlib.

[nim65s]

windows CI still failing with unrelated:

C:\Miniconda\envs\pinocchio\Library\include\cppad/cg/cg.hpp(200): error C2063: 'CppAD::cg::operator *': not a function
C:\Miniconda\envs\pinocchio\Library\include\cppad/cg/base_double.hpp(27): note: see reference to class template instantiation 'CppAD::cg::CG<double>' being compiled
C:\Miniconda\envs\pinocchio\Library\include\cppad/cg/cg.hpp(217): error C2143: syntax error: missing ';' before '<'
C:\Miniconda\envs\pinocchio\Library\include\cppad/cg/cg.hpp(217): error C2433: 'CppAD::cg::NearEqual': 'friend' not permitted on data declarations
C:\Miniconda\envs\pinocchio\Library\include\cppad/cg/cg.hpp(217): error C2365: 'CppAD::cg::NearEqual': redefinition; previous definition was 'function'

[jorisv]

build_all label is adding -DBUILD_WITH_CODEGEN_SUPPORT=ON on Windows but this option is not allowed on this OS.

We will fix this.