Refactor Codecov CI job

[tautschnig]

Please review commit-by-commit.

• Each commit message has a non-empty body, explaining why the change was made.
• n/a Methods or procedures I have added are documented, following the guidelines provided in CODING_STANDARD.md.
• n/a The feature or user visible behaviour I have added or modified has been documented in the User Guide in doc/cprover-manual/
• Regression or unit tests are included, or existing tests cover the modified code (in this case I have detailed which ones those are in the commit message).
• My commit message includes data points confirming performance improvements (if claimed).
• My PR is restricted to a single feature or bugfix.
• n/a White-space or formatting changes outside the feature-related changed lines are in commits of their own.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 78.10%. Comparing base (cbc5079) to head (62cf283).

❗ Current head 62cf283 differs from pull request most recent head 9fa738a

Please upload reports for the commit 9fa738a to get more accurate results.

Additional details and impacted files

@@             Coverage Diff             @@
##           develop    #8339      +/-   ##
===========================================
- Coverage    78.35%   78.10%   -0.26%     
===========================================
  Files         1726     1726              
  Lines       188405   189040     +635     
  Branches     18446    18352      -94     
===========================================
+ Hits        147634   147645      +11     
- Misses       40771    41395     +624     

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