Bump octicons from 19.19.0 to 19.21.1

Bumps [octicons](https://github.com/primer/octicons_gem) from 19.19.0 to 19.21.1.
- [Commits](https://github.com/primer/octicons_gem/commits)

---
updated-dependencies:
- dependency-name: octicons
  dependency-version: 19.21.1
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

Gemfile.lock

@@ -154,7 +154,7 @@ GEM
       racc (~> 1.4)
     nokogiri (1.18.9-x86_64-linux-gnu)
       racc (~> 1.4)
-    octicons (19.19.0)
+    octicons (19.21.1)
     parallel (1.27.0)
     parser (3.3.9.0)
       ast (~> 2.4.1)