ci(pr-labeler): replace TimonVS/pr-labeler-action

Replace the `TimonVS/pr-labeler-action` with
`release-drafter/release-drafter` as it has an [`autolabeler`][1]
option that can autolabel PRs for us.

This should fix labeling PRs from forks,
see https://github.com/TimonVS/pr-labeler-action/issues/25.

I've kept the `.github/pr-labeler.yml` configuration file, so that
links to it from the https://mermaid.js.org website continue to work.

I've also kept everything in the same
`.github/workflows/pr-labeler.yml` GitHub Actions workflow to make the
`git diff` easier to review, and to keep the GitHub Actions permissions
the same.

[1]: ff929b5ceb/README.md (autolabeler)

.github/workflows/pr-labeler.yml

@@ -9,7 +9,7 @@ on:
     # Please read the following first before reviewing/merging:
     # - https://docs.github.com/en/actions/using-workflows/events-that-trigger-workflows#pull_request_target
     # - https://securitylab.github.com/research/github-actions-preventing-pwn-requests/
-    types: [opened]
+    types: [opened, reopened, synchronize]
 
 permissions:
   contents: read
@@ -22,6 +22,10 @@ jobs:
       pull-requests: write # write permission is required to label PRs
     steps:
       - name: Label PR
-        uses: TimonVS/pr-labeler-action@v4
+        uses: release-drafter/release-drafter@v5
+        with:
+          config-name: pr-labeler.yml
+          disable-autolabeler: false
+          disable-releaser: true
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}