Bump sprockets-rails from 3.2.2 to 3.4.0 (#16990)

Bumps [sprockets-rails](https://github.com/rails/sprockets-rails) from 3.2.2 to 3.4.0.
- [Release notes](https://github.com/rails/sprockets-rails/releases)
- [Commits](https://github.com/rails/sprockets-rails/compare/v3.2.2...v3.4.0)

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

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

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Gemfile.lock

@@ -583,9 +583,9 @@ GEM
     sprockets (3.7.2)
       concurrent-ruby (~> 1.0)
       rack (> 1, < 3)
-    sprockets-rails (3.2.2)
-      actionpack (>= 4.0)
-      activesupport (>= 4.0)
+    sprockets-rails (3.4.0)
+      actionpack (>= 5.2)
+      activesupport (>= 5.2)
       sprockets (>= 3.0.0)
     sshkit (1.21.2)
       net-scp (>= 1.1.2)
@@ -774,7 +774,7 @@ DEPENDENCIES
   simple_form (~> 5.1)
   simplecov (~> 0.21)
   sprockets (~> 3.7.2)
-  sprockets-rails (~> 3.2)
+  sprockets-rails (~> 3.4)
   stackprof
   stoplight (~> 2.2.1)
   strong_migrations (~> 0.7)