Automerge: Reapply "[Github] Update PR labeller to v6.0.1 (#167246)"

This reverts commit d772663.

This fixes the final issue with the labeller landing. There were
two remaining issues:
1. There was an extra quote on one of the globs
2. Some of the yaml keys were named incorrectly (should have been
   plural)

Author: boomanaiden154