ci: update backport assistant to 0.3.4 (#17486)

.github/workflows/backport-assistant.yml

@@ -19,7 +19,7 @@ jobs:
   backport:
     if: github.event.pull_request.merged
     runs-on: ubuntu-latest
-    container: hashicorpdev/backport-assistant:0.3.3
+    container: hashicorpdev/backport-assistant:0.3.4
     steps:
       - name: Run Backport Assistant for release branches
         run: |
@@ -40,4 +40,4 @@ jobs:
           curl -s -H "Authorization: token ${{ secrets.PR_COMMENT_TOKEN }}" \
             -X POST \
             -d "{ \"body\": \"${github_message}\"}" \
-            "https://api.github.com/repos/${GITHUB_REPOSITORY}/pull/${{ github.event.pull_request.number }}/comments"
+            "https://api.github.com/repos/${GITHUB_REPOSITORY}/pull/${{ github.event.pull_request.number }}/comments"