fix: don’t update lock file maintenance or create PR out of schedule

Do no lock file maintenance work even if branch exists.

Closes #2503

lib/workers/branch/index.js

@@ -118,6 +118,11 @@ async function processBranch(branchConfig, packageFiles) {
         logger.debug('Skipping branch update as not within schedule');
         return 'not-scheduled';
       }
+      // istanbul ignore if
+      if (config.updateType === 'lockFileMaintenance') {
+        logger.debug('Skipping Lock file maintenance out of schedule');
+        return 'not-scheduled';
+      }
       logger.debug(
         'Branch exists but is not scheduled -- will update if necessary'
       );