perf: pinned python dependency count check

[huniafatima-arbi]

Description:

This PR adds the check to count the number of pinned python dependencies from constraints.tx or common-constraints.txt files. The key is pinned_python_dependencies

Merge checklist:

• Changelog record added
• Documentation updated (not only docstrings)
• Commits are squashed

[codecov]

Codecov Report

Attention: Patch coverage is 0% with 24 lines in your changes missing coverage. Please review.

Project coverage is 73.98%. Comparing base (98b78ad) to head (c45d135).
Report is 5 commits behind head on master.

Files with missing lines	Patch %	Lines
repo_health/check_pinned_python_dependencies.py	0.00%	22 Missing ⚠️
repo_health/check_ubuntufiles.py	0.00%	1 Missing ⚠️
repo_health/utils.py	0.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #509      +/-   ##
==========================================
- Coverage   75.08%   73.98%   -1.10%     
==========================================
  Files          26       27       +1     
  Lines        1513     1534      +21     
==========================================
- Hits         1136     1135       -1     
- Misses        377      399      +22     

Flag	Coverage Δ
unittests	73.98% <0.00%> (-1.10%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

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