.gitlabci.yml: Reduce api test runners

Only rhel ga and centos-8 are being built by the service.

.gitlab-ci.yml

@@ -295,24 +295,9 @@ API:
   parallel:
     matrix:
       - <<: *API_TESTS
-        RUNNER:
-          - aws/fedora-33-x86_64
-          # See COMPOSER-919
-          # - aws/fedora-34-x86_64
-          # See COMPOSER-1118
-          # - aws/centos-stream-8-x86_64
-      - TARGET:
-          - aws
-          - gcp
-          - aws.s3
         RUNNER:
           - aws/centos-stream-8-x86_64
-      - <<: *API_TESTS
-        RUNNER:
           - aws/rhel-8.4-ga-x86_64
-          - aws/rhel-8.6-nightly-x86_64
-          - aws/rhel-9.0-nightly-x86_64
-        INTERNAL_NETWORK: ["true"]
 
 libvirt:
   stage: test