DEV: Bump sidekiq from 6.0.4 to 6.0.5 (#8964)

Bumps [sidekiq](https://github.com/mperham/sidekiq) from 6.0.4 to 6.0.5.
- [Release notes](https://github.com/mperham/sidekiq/releases)
- [Changelog](https://github.com/mperham/sidekiq/blob/master/Changes.md)
- [Commits](sidekiq/sidekiq@v6.0.4...v6.0.5)

Changes are safe, mostly around 2.7 support

Gemfile.lock

@@ -372,9 +372,9 @@ GEM
       activesupport (>= 3.1)
     shoulda-matchers (4.2.0)
       activesupport (>= 4.2.0)
-    sidekiq (6.0.4)
+    sidekiq (6.0.5)
       connection_pool (>= 2.2.2)
-      rack (>= 2.0.0)
+      rack (~> 2.0)
       rack-protection (>= 2.0.0)
       redis (>= 4.1.0)
     simplecov (0.18.2)