Remove PR labeler bot (pydata#8525)

* remove labeler bot config

* remove labeler workflows

* revert pydata#7431

Author: TomNicholas

.github/labeler.yml

@@ -7,7 +7,7 @@ on:
 
 jobs:
   benchmark:
-    if: ${{ contains( github.event.pull_request.labels.*.name, 'run-benchmark') && github.event_name == 'pull_request' || contains( github.event.pull_request.labels.*.name, 'topic-performance') && github.event_name == 'pull_request' || github.event_name == 'workflow_dispatch' }}
+    if: ${{ contains( github.event.pull_request.labels.*.name, 'run-benchmark') && github.event_name == 'pull_request' || github.event_name == 'workflow_dispatch' }}
     name: Linux
     runs-on: ubuntu-20.04
     env: