Bump pascalgn/automerge-action from 0.16.0 to 0.16.4

Bumps [pascalgn/automerge-action](https://github.com/pascalgn/automerge-action) from 0.16.0 to 0.16.4.
- [Release notes](https://github.com/pascalgn/automerge-action/releases)
- [Commits](pascalgn/automerge-action@v0.16.0...v0.16.4)

---
updated-dependencies:
- dependency-name: pascalgn/automerge-action
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <support@github.com>

.github/workflows/automerge.yml

@@ -12,7 +12,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: automerge
-        uses: "pascalgn/automerge-action@v0.16.0"
+        uses: "pascalgn/automerge-action@v0.16.4"
         env:
           GITHUB_TOKEN: "${{ secrets.GITHUB_TOKEN }}"
           MERGE_METHOD: squash