[BUG] Uploaded coverage reports missing, out of date report "latest" on `main` branch

Describe the bug

The action reports that coverage reports are successfully uploaded. Navigating to the url from the logs shows no uploads.

Additionally, the "latest" commit on main is out of date by a full week and we can't figure out why or how to update it.

To Reproduce
Steps to reproduce the "missing successful uploads" behavior:

1. Commit https://github.com/carbon-design-system/carbon/commit/7659f5df1cba1eaea86858b8de022ddd2619003f was merged as part of a merge_group via GitHub's Merge Queue feature.
2. View the log for this here: https://github.com/carbon-design-system/carbon/actions/runs/16779700173/job/47514731976#step:9:243
   *

   info - 2025-08-06 14:42:11,650 -- ci service found: github-actions
   warning - 2025-08-06 14:42:11,722 -- xcrun is not installed or can't be found.
   warning - 2025-08-06 14:42:15,244 -- No gcov data found.
   warning - 2025-08-06 14:42:15,244 -- coverage.py is not installed or can't be found.
   info - 2025-08-06 14:42:17,339 -- Found 3 coverage files to report
   info - 2025-08-06 14:42:17,340 -- > /home/runner/work/carbon/carbon/coverage/lcov.info
   info - 2025-08-06 14:42:17,340 -- > /home/runner/work/carbon/carbon/coverage/clover.xml
   info - 2025-08-06 14:42:17,340 -- > /home/runner/work/carbon/carbon/coverage/coverage-final.json
   info - 2025-08-06 14:42:17,938 -- Your upload is now processing. When finished, results will be available at: https://app.codecov.io/github/carbon-design-system/carbon/commit/7659f5df1cba1eaea86858b8de022ddd2619003f
   info - 2025-08-06 14:42:18,122 -- Process Upload complete
   

3. Click on the "results available" url - it shows no uploads when it should

Steps to reproduce the latest commit on main being out of date

1. Go to https://app.codecov.io/gh/carbon-design-system/carbon
2. See latest commit currently shows https://github.com/carbon-design-system/carbon/commit/30b4f874c37a5725bfac3be52b55349a8bbdaaaf
   • 
3. The latest commit in the repo shows different - lots has been merged since then. This ss shows just through Aug 5 - it's Aug 11 and there's even more ahead of this with successful uploads in the logs but no uploads shown in the tool.

Expected behavior

• Uploads should work and be shown in the tool when logs show success upload
• reports for main should be up to date based on these
• codecov status checks should report/pass on PRs (they're not right now)

Regression
Technically this worked 7 days ago (one time) but before that it also had been happening. I don't know when exactly it started but we've had to made the codecov status check non-required for the past week since none of the checks are passing or reporting.

Screenshots
see above

Product Area
coverage

Versions

• OS: mac
• Git Host: GitHub
• CI/CD: GitHub Actions
• Uploader: codecov/codecov-action@18283e04ce6e62d37312384ff67231eb8fd56d24 # v5.4.3

Commit and CI link
see above

Additional context
n/a

Start with the referenced GitHub Actions merge_group run and the codecov/codecov-action@v5.4.3 uploader logs, then compare the reported commit with the Codecov results page for main. Investigate why successful uploads are not displayed or reflected in status checks. Done means uploaded reports appear, main is current, and Codecov checks report correctly on pull requests.