fix(trailing-slash): handle HEAD request in trailing slash middleware

[sushichan044]

The author should do the following, if applicable

closes #4048

Caution

Review should be done on a per-commit basis as test cases were refactored in 808e520
Hiding whitespace is also recommended.

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

[sushichan044]

changed commit message: https://github.com/honojs/hono/compare/a0a97826e957527005bc1003a20b7c88c3ab1566..94038420bcada419c2e8416ae3d2993144c83257

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 91.32%. Comparing base (882e75a) to head (9403842).
Report is 3 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #4049   +/-   ##
=======================================
  Coverage   91.32%   91.32%           
=======================================
  Files         168      168           
  Lines       10684    10689    +5     
  Branches     3032     3023    -9     
=======================================
+ Hits         9757     9762    +5     
  Misses        926      926           
  Partials        1        1           

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[yusukebe]

LGTM!

[yusukebe]

Hey @sushichan044 !

Looks good to me. I'll merge this into the main and release a new version later. Thank you!