chore(core): use latest codecov in github actions

[sehilyi]

Fix #
Toward #

Change List

• Ues v3 codecov-actions

This might address the issue with occasional Codecov error with unfound token issues

{'detail': ErrorDetail(string='Unable to locate build via Github Actions API. Please upload with the Codecov repository upload token to resolve issue.', code='not_found')}
404
==> Uploading to Codecov
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed

  0     0    0     0    0     0      0      0 --:--:-- --:--:-- --:--:--     0
 10 47.2M  100   171   10 5151k    478  14.0M  0:00:03 --:--:--  0:00:03 14.1M
    {'detail': ErrorDetail(string='Unable to locate build via Github Actions API. Please upload with the Codecov repository upload token to resolve issue.', code='not_found')}
Error: Codecov failed with the following error: The process '/usr/bin/bash' failed with exit code 1

cc @thomcsmits

Checklist

• Ensure the PR works with all demos on the online editor
• Unit tests added or updated
• Examples added or updated
• Documentation updated (e.g., added API functions)
• Screenshots for visual changes (e.g., new encoding support or UI change on Editor)