Bump unf_ext from 0.0.9 to 0.0.9.1

Bumps [unf_ext](https://github.com/knu/ruby-unf_ext) from 0.0.9 to 0.0.9.1.
- [Changelog](https://github.com/knu/ruby-unf_ext/blob/master/CHANGELOG.md)
- [Commits](knu/ruby-unf_ext@v0.0.9...v0.0.9.1)

---
updated-dependencies:
- dependency-name: unf_ext
  dependency-type: indirect
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <[email protected]>

Gemfile.lock

@@ -282,7 +282,7 @@ GEM
       thread_safe (~> 0.1)
     unf (0.1.4)
       unf_ext
-    unf_ext (0.0.9)
+    unf_ext (0.0.9.1)
     unicode-display_width (1.8.0)
     webrick (1.8.1)
     yell (2.2.2)