ci: update BPA to disable inactive CE backports (#21214)

Follow-up to #21094, which temporarily downgraded BPA to allow for old
CE backport labels to be used during Consul's most recent patch release.

Upgrading fully enforces the version manifest and prevents accidental
backports to no-longer-active CE versions.

.github/workflows/backport-assistant.yml

@@ -19,10 +19,7 @@ jobs:
   backport:
     if: github.event.pull_request.merged
     runs-on: ubuntu-latest
-    # Temporarily use 0.4.0 to enable old + new label functionality prior
-    # to this fix in BPA that excludes CE labels: https://github.com/hashicorp/backport-assistant/pull/84
-    # After the Consul May patches, this can be removed and the version updated to latest.
-    container: hashicorpdev/backport-assistant:0.4.0
+    container: hashicorpdev/backport-assistant:0.4.1
     steps:
       - name: Run Backport Assistant for release branches
         run: |