fix(request-id): validation accepts =

[ryuapp]

closes #4477

The middleware validation accepts = to use a Base64 string like AWS request id.

The author should do the following, if applicable

• Add tests
• Run tests
• bun run format:fix && bun run lint:fix to format the code
• Add TSDoc/JSDoc to document the code

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 91.30%. Comparing base (4b796cf) to head (8d99dcb).
⚠️ Report is 13 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #4478      +/-   ##
==========================================
- Coverage   91.32%   91.30%   -0.02%     
==========================================
  Files         173      173              
  Lines       11084    11190     +106     
  Branches     3201     3228      +27     
==========================================
+ Hits        10122    10217      +95     
- Misses        961      972      +11     
  Partials        1        1              

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[yusukebe]

LGTM!

[yusukebe]

@ryuapp Thank you for the quick fix!