CI: Update workers fleet

By default CI is running on RHEL 8, F36 and F37 workers.
This commit adds Fedora 38 to the workers list
and removes deprecated Fedora 36

.gitlab-ci.yml

@@ -26,10 +26,10 @@ RPM:
   parallel:
     matrix:
       - RUNNER:
-          - aws/fedora-36-x86_64
-          - aws/fedora-36-aarch64
           - aws/fedora-37-x86_64
           - aws/fedora-37-aarch64
+          - aws/fedora-38-x86_64
+          - aws/fedora-38-aarch64
           - aws/rhel-8.6-ga-x86_64
           - aws/rhel-8.6-ga-aarch64
 
@@ -46,8 +46,8 @@ Testing:
     matrix:
       # https://quay.io/repository/osbuild/postgres available only for x86_64
       - RUNNER:
-          - aws/fedora-36-x86_64
           - aws/fedora-37-x86_64
+          - aws/fedora-38-x86_64
       - RUNNER:
           - aws/rhel-8.6-ga-x86_64
         INTERNAL_NETWORK: ["true"]