fix(renovate): automerge patch versions of used container images in docker files

Dockerfile

@@ -1,4 +1,4 @@
-FROM docker.io/library/rockylinux:9.2
+FROM docker.io/library/rockylinux:9.2.20230513
 
 ARG MKISOFS_VERSION
 

renovate.json

@@ -10,6 +10,14 @@
       "automerge": true,
       "matchManagers": "droneci",
       "matchUpdateTypes": [ "minor", "patch"]
+    },
+    {
+      "description": "Automatically update patch version of used container images in docker files",
+      "addLabels": [ "renovate/container-image", "renovate/automerge" ],
+      "automerge": true,
+      "matchBaseBranches": [ "master" ],
+      "matchManagers": [ "dockerfile" ],
+      "matchUpdateTypes": [ "patch" ]
     }
   ],
   "rebaseLabel": "renovate/rebase",