Simplify and clarify Ruby version related variables we're using/passing

.gitlab-ci.yml

@@ -29,15 +29,15 @@ default:
 
 .old-ruby-variables: &old-ruby-variables
   RUBY_VERSION: "3.0"
-  CACHE_EDITION: "GITLAB_RUBY3_0"
+  OMNIBUS_GITLAB_CACHE_EDITION: "GITLAB_RUBY3_0"
 
 .default-ruby-variables: &default-ruby-variables
   RUBY_VERSION: "3.1"
-  CACHE_EDITION: "GITLAB_RUBY3_1"
+  OMNIBUS_GITLAB_CACHE_EDITION: "GITLAB_RUBY3_1"
 
 .next-ruby-variables: &next-ruby-variables
   RUBY_VERSION: "3.2"
-  CACHE_EDITION: "GITLAB_RUBY3_2"
+  OMNIBUS_GITLAB_CACHE_EDITION: "GITLAB_RUBY3_2"
 
 .default-branch-pipeline-failure-variables: &default-branch-pipeline-failure-variables
   CREATE_RAILS_TEST_FAILURE_ISSUES: "true"

.gitlab/ci/cng/main.gitlab-ci.yml

@@ -54,8 +54,6 @@ include:
     GITLAB_WORKHORSE_VERSION: "${GITLAB_WORKHORSE_VERSION}"
     GITALY_SERVER_VERSION: "${GITALY_SERVER_VERSION}"
     RUBY_VERSION: "${FULL_RUBY_VERSION}"
-    NEXT_RUBY_CACHE_KEY: "${RUBY_VERSION}"
-    NEXT_RUBY_VERSION: "${FULL_RUBY_VERSION}"
   trigger:
     project: ${CI_PROJECT_NAMESPACE}/build/CNG-mirror
     branch: $TRIGGER_BRANCH

.gitlab/ci/qa.gitlab-ci.yml

@@ -90,8 +90,9 @@ trigger-omnibus:
     TOP_UPSTREAM_SOURCE_PROJECT: $CI_PROJECT_PATH
     SECURITY_SOURCES: $SECURITY_SOURCES
     CACHE_UPDATE: $OMNIBUS_GITLAB_CACHE_UPDATE
-    CACHE_EDITION: $CACHE_EDITION
-    NEXT_RUBY_VERSION: $FULL_RUBY_VERSION
+    CACHE_EDITION: $OMNIBUS_GITLAB_CACHE_EDITION
+    USE_SPECIFIED_RUBY_VERSION: "true"
+    RUBY_VERSION: $FULL_RUBY_VERSION
     BUILD_ON_ALL_OS: $OMNIBUS_GITLAB_BUILD_ON_ALL_OS
     SKIP_QA_TEST: "true"
     ee: $EE