ci(renovate): Add mirrored images for upgrades

renovate.json

@@ -32,6 +32,14 @@
       "datasourceTemplate": "docker",
       "versioningTemplate": "docker"
     },
+    {
+      "fileMath": ["images/mirror/Earthfile$"],
+      "matchStrings": [
+        "DO \\+MIRROR --image=\"?'?(?<depName>[^:\\s]+?):(?<currentValue>[^\"]*?)\"?'?\\s"
+      ],
+      "datasourceTemplate": "docker",
+      "versioningTemplate": "docker"
+    },
     {
       "fileMatch": ["\\.yaml$"],
       "matchStrings": [