Fix #2610, Enforce keeping coverage minimums up-to-date in Code Coverage CI workflow

[thnkslprpt]

Checklist

• [x] I reviewed the Contributing Guide.
• [x] I signed and emailed the appropriate Contributor License Agreement to [email protected] and copied [email protected].

Describe the contribution

• Lowers allowed_missed_lines to 17 (from 19)
• Fixes #2610
  • Adds additional steps in the code coverage workflow to check that the missed functions/lines/branches variables are kept up-to-date.

Testing performed Tested all variations of coverage thresholds (above, below, split between functions/lines/branches etc.) to confirm expected behavior.

New checks:

Expected behavior changes Any PR that improves coverage will cause the workflow to fail now unless the ALLOWED_MISSED_BRANCHES, ALLOWED_MISSED_LINES and/or ALLOWED_MISSED_FUNCTIONS variables are updated as part of the same PR. This will avoid cases like the present, where there is a gap, and a new PR could theoretically reduce coverage but give no warning of the fact.

System(s) tested on Debian GNU/Linux 11 (bullseye) Current main branch of cFS bundle.

Contributor Info Avi Weiss   @thnkslprpt