metadata files routines

[vivus-ignis]

What this PR does / why we need it:
Splitting #179 into smaller parts

Which issue(s) this PR fixes:
gardenlinux/gardenlinux#3054

[codecov]

Codecov Report

❌ Patch coverage is 41.81818% with 32 lines in your changes missing coverage. Please review.
✅ Project coverage is 87.66%. Comparing base (4f0eb6b) to head (0dc9b79).
⚠️ Report is 6 commits behind head on main.

Files with missing lines	Patch %	Lines
src/gardenlinux/github/release_notes/helpers.py	31.91%	32 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #206      +/-   ##
==========================================
- Coverage   89.03%   87.66%   -1.37%     
==========================================
  Files          33       33              
  Lines        1495     1549      +54     
==========================================
+ Hits         1331     1358      +27     
- Misses        164      191      +27     

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

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.