Remove resource group for release environments QA

Since the release environments QA jobs run in parallel=5, using resource
group blocks them from running in parallel.

.gitlab/ci/release-environments/main.gitlab-ci.yml

@@ -95,7 +95,6 @@ release-environments-qa:
     GITLAB_INITIAL_ROOT_PASSWORD: "${RELEASE_ENVIRONMENTS_ROOT_PASSWORD}"
     QA_PRAEFECT_REPOSITORY_STORAGE: "default"
     SIGNUP_DISABLED: "true"
-  resource_group: release-environment-${CI_COMMIT_REF_SLUG}
 
 release-environments-notification-failure:
   stage: finish

.gitlab/ci/release-environments/security.gitlab-ci.yml

@@ -98,7 +98,6 @@ release-environments-qa:
     GITLAB_INITIAL_ROOT_PASSWORD: "${RELEASE_ENVIRONMENTS_ROOT_PASSWORD}"
     QA_PRAEFECT_REPOSITORY_STORAGE: "default"
     SIGNUP_DISABLED: "true"
-  resource_group: release-environment-${CI_COMMIT_REF_SLUG}
 
 release-environments-notification-failure:
   stage: finish