Bump bootstrap from 5.3.5 to 5.3.8

Bumps [bootstrap](https://github.com/twbs/bootstrap-rubygem) from 5.3.5 to 5.3.8.
- [Release notes](https://github.com/twbs/bootstrap-rubygem/releases)
- [Changelog](https://github.com/twbs/bootstrap-rubygem/blob/main/CHANGELOG.md)
- [Commits](twbs/bootstrap-rubygem@v5.3.5...v5.3.8)

---
updated-dependencies:
- dependency-name: bootstrap
  dependency-version: 5.3.8
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

Author: dependabot[bot]

Gemfile.lock

@@ -113,7 +113,7 @@ GEM
       zeitwerk
     bootsnap (1.20.1)
       msgpack (~> 1.2)
-    bootstrap (5.3.5)
+    bootstrap (5.3.8)
       popper_js (>= 2.11.8, < 3)
     builder (3.3.0)
     byebug (12.0.0)