chore: bump codecov version

[drmorr0]

• I certify that this PR does not contain any code that has been generated with GitHub Copilot or any other AI-based code generation tool, in accordance with this project's policies.

Description

Remove codecov token to let dependabot still work (see details in the readme, v4 and v5 releases).

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 70.49%. Comparing base (f712955) to head (6f0477f).
Report is 1 commits behind head on master.

Additional details and impacted files

@@           Coverage Diff           @@
##           master     #184   +/-   ##
=======================================
  Coverage   70.49%   70.49%           
=======================================
  Files          57       57           
  Lines        3274     3274           
  Branches     3274     3274           
=======================================
  Hits         2308     2308           
  Misses        794      794           
  Partials      172      172           

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

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.