Test Sidekiq with more Redis versions

We vendored Sidekiq in
https://gitlab.com/gitlab-org/gitlab/-/merge_requests/143563 to
fix Redis 6.0 compatibility. However, we should test our changes
against Redis 6.2 and 7.0 to ensure we didn't break anything.

vendor/gems/sidekiq-7.1.6/.gitlab-ci.yml

@@ -12,9 +12,10 @@ rspec:
   parallel:
     matrix:
       - RUBY_VERSION: ["3.0", "3.1", "3.2"]
+        REDIS_VERSION: ["6.0", "6.2", "7.0"]
 
 .with_redis:
   services:
-    - redis:6.0-alpine
+    - redis:${REDIS_VERSION}-alpine
   variables:
     REDIS_URL: "redis://redis"