Merge branch '350631-use_redis_6_default_and_5_nightly' into 'master'

CI/CD - Test against Redis 6 by default for postgreSQL 12, and keep Redis 5 for other postgreSQL versions

See merge request gitlab-org/gitlab!82019

.gitlab/ci/global.gitlab-ci.yml

@@ -226,7 +226,7 @@
   services:
     - name: postgres:12
       command: ["postgres", "-c", "fsync=off", "-c", "synchronous_commit=off", "-c", "full_page_writes=off"]
-    - name: redis:5.0-alpine
+    - name: redis:6.0-alpine
   variables:
     POSTGRES_HOST_AUTH_METHOD: trust
 
@@ -255,7 +255,7 @@
   services:
     - name: postgres:12
       command: ["postgres", "-c", "fsync=off", "-c", "synchronous_commit=off", "-c", "full_page_writes=off"]
-    - name: redis:5.0-alpine
+    - name: redis:6.0-alpine
     - name: elasticsearch:7.17.0
       command: ["elasticsearch", "-E", "discovery.type=single-node"]
   variables: