Pin microshift build for openshift-4.18 ec.4 (#5728)

Created by job run https://art-jenkins.apps.prod-stable-spoke1-dc-iad2.itup.redhat.com/job/aos-cd-builds/job/build%252Fbuild-microshift/1407

Co-authored-by: AOS Automation Release Team <[email protected]>

releases.yml

@@ -24,7 +24,12 @@ releases:
         component: '*'
       members:
         images: []
-        rpms: []
+        rpms:
+        - distgit_key: microshift
+          why: Pin microshift to assembly
+          metadata:
+            is:
+              el9: microshift-4.18.0~ec.4-202411221636.p0.gbfd3ba1.assembly.ec.4.el9
       rhcos:
         rhel-coreos:
           images: