Raise ValueError in phone validator

[armanddidierjean]

to let FastAPI return Pydantic ValidationError instead of crashing

Checklist

• Created tests which fail without the change (if possible)
• All tests passing
• Extended the documentation, if necessary

[codecov]

Codecov Report

Attention: Patch coverage is 33.33333% with 4 lines in your changes missing coverage. Please review.

Project coverage is 81.57%. Comparing base (e0c8337) to head (93e7df1).

Files with missing lines	Patch %	Lines
app/utils/validators.py	33.33%	4 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #552      +/-   ##
==========================================
- Coverage   81.58%   81.57%   -0.02%     
==========================================
  Files         125      125              
  Lines        9823     9822       -1     
==========================================
- Hits         8014     8012       -2     
- Misses       1809     1810       +1     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.