Use deco-testing runner group for Claude Code dispatch

The databricks-eng org has a GitHub IP allowlist that blocks
ubuntu-latest runners from generating GitHub App tokens. Switch
to databricks-deco-testing-runner-group (with ubuntu-latest-deco
label) which has allowlisted IPs, matching the pattern used by
start-integration-tests.yml and other dispatch workflows.

Co-authored-by: Isaac

Author: shreyas-goenka

.github/workflows/claude-code.yml

@@ -21,7 +21,9 @@ jobs:
   # Automatic PR review when a PR is opened or updated.
   review:
     if: github.event_name == 'pull_request'
-    runs-on: ubuntu-latest
+    runs-on:
+      group: databricks-deco-testing-runner-group
+      labels: ubuntu-latest-deco
     environment: test-trigger-is
     permissions:
       contents: read
@@ -51,7 +53,9 @@ jobs:
     if: |
       (github.event_name == 'issue_comment' && contains(github.event.comment.body, '@claude')) ||
       (github.event_name == 'pull_request_review_comment' && contains(github.event.comment.body, '@claude'))
-    runs-on: ubuntu-latest
+    runs-on:
+      group: databricks-deco-testing-runner-group
+      labels: ubuntu-latest-deco
     environment: test-trigger-is
     permissions:
       contents: read