Fix various Cython warning and deprecation notices

[benoit74]

See list of commits for details

To be merged after #237

Goal is to get rid of these warnings

  /tmp/build-env-ltwgiw2r/lib/python3.10/site-packages/setuptools/config/_apply_pyprojecttoml.py:82: SetuptoolsDeprecationWarning: `project.license` as a TOML table is deprecated
  !!
  
          ********************************************************************************
          Please use a simple string containing a SPDX expression for `project.license`. You can also use `project.license-files`. (Both options available on setuptools>=77.0.0).
  
          By 2026-Feb-18, you need to update your project and remove deprecated calls
          or your builds will no longer be supported.
  
          See https://packaging.python.org/en/latest/guides/writing-pyproject-toml/#license for details.
          ********************************************************************************
  
  !!
    corresp(dist, value, root_dir)
  /tmp/build-env-ltwgiw2r/lib/python3.10/site-packages/setuptools/config/_apply_pyprojecttoml.py:61: SetuptoolsDeprecationWarning: License classifiers are deprecated.
  !!
  
          ********************************************************************************
          Please consider removing the following classifiers in favor of a SPDX license expression:
  
          License :: OSI Approved :: GNU General Public License v3 or later (GPLv3+)
  
          See https://packaging.python.org/en/latest/guides/writing-pyproject-toml/#license for details.
          ********************************************************************************
  
  !!
    dist._finalize_license_expression()
  /tmp/build-env-ltwgiw2r/lib/python3.10/site-packages/setuptools/dist.py:759: SetuptoolsDeprecationWarning: License classifiers are deprecated.
  !!
  
          ********************************************************************************
          Please consider removing the following classifiers in favor of a SPDX license expression:
  
          License :: OSI Approved :: GNU General Public License v3 or later (GPLv3+)
  
          See https://packaging.python.org/en/latest/guides/writing-pyproject-toml/#license for details.
          ********************************************************************************
  
  !!

And these warnings:

  warning: libzim/zim.pxd:69:61: The keyword 'nogil' should appear at the end of the function signature line. Placing it before 'except' or 'noexcept' will be disallowed in a future version of Cython.
  warning: libzim/zim.pxd:70:64: The keyword 'nogil' should appear at the end of the function signature line. Placing it before 'except' or 'noexcept' will be disallowed in a future version of Cython.
  warning: libzim/zim.pxd:71:85: The keyword 'nogil' should appear at the end of the function signature line. Placing it before 'except' or 'noexcept' will be disallowed in a future version of Cython.
  warning: libzim/zim.pxd:72:119: The keyword 'nogil' should appear at the end of the function signature line. Placing it before 'except' or 'noexcept' will be disallowed in a future version of Cython.
  warning: libzim/zim.pxd:74:47: The keyword 'nogil' should appear at the end of the function signature line. Placing it before 'except' or 'noexcept' will be disallowed in a future version of Cython.
  warning: libzim/zim.pxd:76:78: The keyword 'nogil' should appear at the end of the function signature line. Placing it before 'except' or 'noexcept' will be disallowed in a future version of Cython.

and these ones:

  warning: libzim/libzim.pyx:286:52: Unknown type declaration 'Creator' in annotation, ignoring
  warning: libzim/libzim.pyx:300:62: Unknown type declaration 'Creator' in annotation, ignoring
  warning: libzim/libzim.pyx:316:53: Unknown type declaration 'Creator' in annotation, ignoring
  warning: libzim/libzim.pyx:335:73: Unknown type declaration 'Creator' in annotation, ignoring
  warning: libzim/libzim.pyx:350:56: Unknown type declaration 'Creator' in annotation, ignoring
  warning: libzim/libzim.pyx:364:49: Unknown type declaration 'Creator' in annotation, ignoring
  warning: libzim/libzim.pyx:394:45: Unknown type declaration 'BaseWritingItem' in annotation, ignoring

Perfomance hints are not solved:

  performance hint: libzim/libzim.pyx:101:4: Exception check on 'string_cy_call_fct' will always require the GIL to be acquired. Declare 'string_cy_call_fct' as 'noexcept' if you control the definition and you're sure you don't want the function to raise exceptions.
  performance hint: libzim/libzim.pyx:110:4: Exception check on 'blob_cy_call_fct' will always require the GIL to be acquired. Declare 'blob_cy_call_fct' as 'noexcept' if you control the definition and you're sure you don't want the function to raise exceptions.
  performance hint: libzim/libzim.pyx:176:4: Exception check on 'geoposition_cy_call_fct' will always require the GIL to be acquired. Declare 'geoposition_cy_call_fct' as 'noexcept' if you control the definition and you're sure you don't want the function to raise exceptions.
  performance hint: libzim/libzim.pyx:194:4: Exception check on 'hints_cy_call_fct' will always require the GIL to be acquired. Declare 'hints_cy_call_fct' as 'noexcept' if you control the definition and you're sure you don't want the function to raise exceptions.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 93.69%. Comparing base (f2b3a59) to head (dbfc2f9).
⚠️ Report is 7 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #239   +/-   ##
=======================================
  Coverage   93.69%   93.69%           
=======================================
  Files           1        1           
  Lines         539      539           
=======================================
  Hits          505      505           
  Misses         34       34           

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[rgaudin]

Great work! Always annoyed me, never had the courage to face it.