[core] plugins: Do not use Python 3.10-and-over syntax

[cbentejac]

Description

This PR removes specific code that is Python 3.10 and over-compatible in the plugins module. This is motivated by the fact that meshroom_compute imports the plugins module and can be executed with a Python interpreter that is older than Python 3.10 (e.g. 3.9) when in the context of plugins. Python 3.10 code will raise a SyntaxError, thus causing meshroom_compute to fail in that context.

Although Meshroom is leaning towards supporting only Python 3.10 and over, the plugins module needs to also be compatible with older Python versions, hence the replacement of the match/case syntax with if/elif.

To prevent introducing some version-specific syntax that may affect meshroom_compute, the continous integration workflow, which runs on Python 3.11, is updated to include a step that will attempt to run meshroom_compute (and thus run through the import statements that may cause syntax errors) with Python 3.9.

[codecov]

Codecov Report

❌ Patch coverage is 0% with 7 lines in your changes missing coverage. Please review.
✅ Project coverage is 79.54%. Comparing base (8d1b9ef) to head (6f4b900).
⚠️ Report is 3 commits behind head on develop.
✅ All tests successful. No failed tests found.

Files with missing lines	Patch %	Lines
meshroom/core/plugins.py	0.00%	7 Missing ⚠️

❌ Your patch status has failed because the patch coverage (0.00%) is below the target coverage (70.00%). You can increase the patch coverage or adjust the target coverage.

Additional details and impacted files

@@             Coverage Diff             @@
##           develop    #2909      +/-   ##
===========================================
+ Coverage    79.52%   79.54%   +0.01%     
===========================================
  Files           51       51              
  Lines         6976     6975       -1     
===========================================
  Hits          5548     5548              
+ Misses        1428     1427       -1     

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