Bump jsbundling-rails from 1.1.2 to 1.2.1

Bumps [jsbundling-rails](https://github.com/rails/jsbundling-rails) from 1.1.2 to 1.2.1.
- [Release notes](https://github.com/rails/jsbundling-rails/releases)
- [Commits](rails/jsbundling-rails@v1.1.2...v1.2.1)

---
updated-dependencies:
- dependency-name: jsbundling-rails
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Gemfile.lock

@@ -240,7 +240,7 @@ GEM
     i18n (1.14.1)
       concurrent-ruby (~> 1.0)
     jaro_winkler (1.5.6)
-    jsbundling-rails (1.1.2)
+    jsbundling-rails (1.2.1)
       railties (>= 6.0.0)
     json (2.6.3)
     jwt (2.7.1)