chore(renovate): add pr labels

Add a label in order to pass the test for required labels.

Author: rarkins

renovate.json

@@ -2,5 +2,6 @@
     "extends": ["github>netlify/renovate-config:default"],
     "ignorePresets": [":prHourlyLimit2"],
     "semanticCommits": true,
+    "labels": ["dependencies"],
     "masterIssue": true
-}
+}