Enable promo-based Piwigo groups

[Marc-Andrieu]

Add the promo to the "groups" claim of OIDC's "API" scope in Piwigo's auth client

[codecov]

Codecov Report

❌ Patch coverage is 0% with 1 line in your changes missing coverage. Please review.
✅ Project coverage is 90.20%. Comparing base (62704b0) to head (b8b448a).
⚠️ Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
app/utils/auth/providers.py	0.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #824      +/-   ##
==========================================
- Coverage   90.21%   90.20%   -0.01%     
==========================================
  Files         229      229              
  Lines       22090    22091       +1     
==========================================
  Hits        19928    19928              
- Misses       2162     2163       +1     

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[Rotheem]

We might want to filter promotions being sent with the format 20xx as many users have wrongly formatted ones and each will create a useless group in piwigo