Update job-config.json - Remove support for OpenShift v4.12

Author: SDawley

dependencies/job-config.json

@@ -579,22 +579,19 @@
         "v4.17",
         "v4.16",
         "v4.15",
-        "v4.14",
-        "v4.12"
+        "v4.14"
       ],
       "3.19": [
         "v4.17",
         "v4.16",
         "v4.15",
-        "v4.14",
-        "v4.12"
+        "v4.14"
       ],
       "3.x": [
         "v4.17",
         "v4.16",
         "v4.15",
-        "v4.14",
-        "v4.12"
+        "v4.14"
       ]
     },
     "OPENSHIFT_CONTENT_SET_VERSION": {