Bump octicons from 19.23.1 to 19.25.0 in /demo

Bumps [octicons](https://github.com/primer/octicons_gem) from 19.23.1 to 19.25.0.
- [Commits](https://github.com/primer/octicons_gem/commits)

---
updated-dependencies:
- dependency-name: octicons
  dependency-version: 19.25.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

demo/Gemfile.lock

@@ -252,7 +252,7 @@ GEM
       racc (~> 1.4)
     nokogiri (1.19.3-x86_64-linux-gnu)
       racc (~> 1.4)
-    octicons (19.23.1)
+    octicons (19.25.0)
     oj (3.16.10)
       bigdecimal (>= 3.0)
       ostruct (>= 0.2)