fix(default): ignore maintainLockFilesWeekly preset

* Renovate v43 enables weekly lock file maintenance updates by default;
  ignore this default for the time being until we decide how to handle this

Author: dafyddj

default.json

@@ -6,6 +6,9 @@
     "config:best-practices",
     ":approveMajorUpdates"
   ],
+  "ignorePresets": [
+    ":maintainLockFilesWeekly"
+  ],
   "automergeStrategy": "merge-commit",
   "dependencyDashboardTitle": "Renovate Dashboard"
 }