Revert "Add PR labels based on files changed (#1127)" (#1128)

This reverts commit c296b4c348.

.github/workflows/pr-labels.yaml

@@ -1,24 +0,0 @@
-name: PR labels
-
-on: [pull_request]
-
-
-jobs:
-  pr-label:
-    runs-on: ubuntu-latest
-    name: PR label
-    steps:
-    - uses: actions/checkout@v2
-      with:
-        fetch-depth: 0
-    - id: pr_labels
-      run: script/pr-labels ${{ github.event.pull_request.base.sha }} ${{ github.event.pull_request.head.sha }}
-    - uses: octokit/request-action@v2.0.7
-      if: ${{ steps.pr_labels.outputs.labels != '[""]' }}
-      with:
-        route: POST /repos/:repository/issues/:number/labels
-        number: ${{ github.event.number }}
-        repository: ${{ github.repository }}
-        labels: ${{ steps.pr_labels.outputs.labels }}
-      env:
-        GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}