Bump tailwind_merge from 1.4.0 to 1.5.1 in /gem (#398)

Bumps [tailwind_merge](https://github.com/gjtorikian/tailwind_merge) from 1.4.0 to 1.5.1.
- [Release notes](https://github.com/gjtorikian/tailwind_merge/releases)
- [Changelog](https://github.com/gjtorikian/tailwind_merge/blob/main/CHANGELOG.md)
- [Commits](gjtorikian/tailwind_merge@v1.4.0...v1.5.1)

---
updated-dependencies:
- dependency-name: tailwind_merge
  dependency-version: 1.5.1
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

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Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

gem/Gemfile.lock

@@ -62,7 +62,7 @@ GEM
     standard-performance (1.9.0)
       lint_roller (~> 1.1)
       rubocop-performance (~> 1.26.0)
-    tailwind_merge (1.4.0)
+    tailwind_merge (1.5.1)
       sin_lru_redux (~> 2.5)
     unicode-display_width (3.2.0)
       unicode-emoji (~> 4.1)