fail CI if coverage fails to upload

[timmysilv]

Context:
When the Codecov upload action fails because of network issues or the like, the action reports as passed, then the codecov action stays as "Expected" forevermore. This is worse than a failure because it continues to block us but we don't immediately know why. If we knew, we could just re-run it when we find out.

Description of the Change:
Set the codecov upload action to fail on failure 😄

Benefits:
We will know when it fails to upload, and we can re-run the upload task manually

Possible Drawbacks:
External contributors might hit this, and although the old ways were also bad, this might be a bit more visibly frightening if you don't know why you got a big red ❌

[github-actions]

Hello. You may have forgotten to update the changelog!
Please edit doc/releases/changelog-dev.md with:

• A one-to-two sentence description of the change. You may include a small working example for new features.
• A link back to this PR.
• Your name (or GitHub username) in the contributors section.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Comparison is base (4e2e344) 99.68% compared to head (71501d2) 99.67%.
Report is 1 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #5101      +/-   ##
==========================================
- Coverage   99.68%   99.67%   -0.02%     
==========================================
  Files         392      392              
  Lines       35844    35578     -266     
==========================================
- Hits        35732    35463     -269     
- Misses        112      115       +3     

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

[mudit2812]

Excited to see this change. Too bad we can't test it out