fix: use OIDC for Codecov

[ThirdEyeSqueegee]

Issue #, if available:

Description of changes:
Code coverage broke due to GitHub separating repository secrets from Dependabot secrets. Use the OIDC token to write code coverage data to Codecov.

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[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 90.86%. Comparing base (b85d5e2) to head (b3a69f9).
⚠️ Report is 1 commits behind head on v2.

Additional details and impacted files

@@            Coverage Diff            @@
##                 v2     #167   +/-   ##
=========================================
  Coverage     90.86%   90.86%           
  Complexity       90       90           
=========================================
  Files             6        6           
  Lines           230      230           
  Branches         24       24           
=========================================
  Hits            209      209           
  Misses           18       18           
  Partials          3        3           

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