Mark functions as noexcept to support Cython 3

[matusvalo]

Description

This PR marks functions as noexcept. noexcept keyword was introduced in Cython 3.0 b1 and Cython 0.29.31 to explicitly declare function as not propagating exceptions.This is important because exceptions are propagated by default in Cython3 [1]. Following functions are marked as noexcept in this PR:

• functions having void return type - function returning void in Cython 3 is by default checking an exception after every call. This can possibly end up as performance degradation when function is also marked as nogil - see [1] for details.
• inline functions - inline functions should be performance sensitive so I marked them as noexcept to avoid any (even minor) overhead

Note: This PR is not changing anything for Cython 0.29.X (and therefore should be 100% safe) because noexcept
keyword is ignored (since is equal to default error handling behaviour) in Cython 0.29.X.

This PR is bumping Cython version to 0.29.32. For compilation with Cython3, master branch or Cython 3.0 beta 3 (not released in time of creating this PR) should be used.

[1] https://cython.readthedocs.io/en/latest/src/userguide/migrating_to_cy30.html#exception-values-and-noexcept
[2] https://cython.readthedocs.io/en/latest/src/userguide/language_basics.html#error-return-values

Checklist

• Docstrings for all functions
• Gallery example in ./doc/examples (new features only)
• Benchmark in ./benchmarks, if your changes aren't covered by an
  existing benchmark
• Unit tests
• Clean style in the spirit of PEP8
• Descriptive commit messages (see below)

For reviewers

• Check that the PR title is short, concise, and will make sense 1 year
  later.
• Check that new functions are imported in corresponding __init__.py.
• Check that new features, API changes, and deprecations are mentioned in
  doc/release/release_dev.rst.
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  example, to backport to v0.19.x after merging, add the following in a PR
  comment: @meeseeksdev backport to v0.19.x
• To run benchmarks on a PR, add the run-benchmark label. To rerun, the label
  can be removed and then added again. The benchmark output can be checked in
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[stefanv]

Thanks @matusvalo, this is very helpful!