Update GitHub Actions workflows. (#600)

This PR was automatically generated by the
update-workflows-ecosystem-providers workflow in the pulumi/ci-mgmt
repo, from commit 18861993ff74b54f79ab91da326a133c6ca37001.

.github/workflows/command-dispatch.yml

@@ -28,7 +28,7 @@ jobs:
     steps:
     - name: Checkout Repo
       uses: actions/checkout@v4
-    - uses: peter-evans/slash-command-dispatch@v2
+    - uses: peter-evans/slash-command-dispatch@v4
       with:
         commands: |
           run-acceptance-tests