Codecov action update to support new token format

[jake-skipper]

Summary

Updating codecov action to use the token field defined on their readme. Seems the environment variable is no longer working as runs report no token supplied.

Why This Is Needed

Will hopefully fix the numerous Codecov failures in actions runs.

Checklist

• Have you followed the guidelines in our Contribution Requirements?
• Have you checked to ensure there aren't other open Pull Requests for the same update/change?
• Does your submission pass tests?
• Have you linted your code locally prior to submission?
• Have you added an explanation of what your changes do and why you'd like us to include them?
• Have you written new tests for your core changes, as applicable?
• Have you successfully ran tests with your changes locally?
• Have you updated documentation, as applicable?

[codecov]

Codecov Report

Merging #2056 (3e6efdc) into master (ce3b7d1) will not change coverage.
The diff coverage is n/a.

Additional details and impacted files

@@           Coverage Diff           @@
##           master    #2056   +/-   ##
=======================================
  Coverage   90.18%   90.18%           
=======================================
  Files         247      247           
  Lines       15681    15681           
=======================================
  Hits        14142    14142           
  Misses       1539     1539           

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