Update ZedThree/clang-tidy-review to version 0.21.0

[mcbarton]

Description

Please include a summary of changes, motivation and context for this PR.

This PR updates ZedThree/clang-tidy-review to version 0.21.0 due this issue in version 0.20.1 ZedThree/clang-tidy-review#144

I've put the same PR in xeus-cpp here compiler-research/xeus-cpp#284

Fixes # (issue)

Type of change

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• Bug fix
• New feature
• Requires documentation updates

Testing

Please describe the test(s) that you added and ran to verify your changes.

Checklist

• I have read the contribution guide recently

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 75.94%. Comparing base (58be79c) to head (72db0ec).
Report is 1 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #554   +/-   ##
=======================================
  Coverage   75.94%   75.94%           
=======================================
  Files           9        9           
  Lines        3646     3646           
=======================================
  Hits         2769     2769           
  Misses        877      877           

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[Vipul-Cariappa]

LGTM!