ci: multi-arch-build: enable the build of package index + various fixes

[a-gave]

update gh-action-sdk from v5 to v7
prevent that entire workflow fail if a single arch fails
allow to run the workflow manually
disable unnecessary options: default_feed, patches refresh_check, '*.init' files formatting

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 79.76%. Comparing base (d3d2086) to head (0faa84e).

❗ Current head 0faa84e differs from pull request most recent head 985e11e. Consider uploading reports for the commit 985e11e to get more accurate results

❗ Your organization needs to install the Codecov GitHub app to enable full functionality.

Additional details and impacted files

@@           Coverage Diff           @@
##           master    #1095   +/-   ##
=======================================
  Coverage   79.76%   79.76%           
=======================================
  Files          53       53           
  Lines        4577     4577           
=======================================
  Hits         3651     3651           
  Misses        926      926           

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