fix: use printf to avoid multi-line YAML literal block break

The multi-line --body string had cc @cpfarhood at column 0, which
terminated the YAML literal block scalar prematurely and caused
actionlint to reject the workflow file. Use printf to construct
the body string without embedding a literal newline in the YAML.

Co-Authored-By: Paperclip <noreply@paperclip.ing>

.github/workflows/plugin-release.yaml

@@ -213,11 +213,10 @@ jobs:
       - name: Create PR for version bump
         run: |
           VERSION="${{ inputs.version }}"
+          BODY=$(printf "Automated version bump and checksum update for v%s.\n\ncc @cpfarhood" "${VERSION}")
           gh pr create \
             --title "release: v${VERSION}" \
-            --body "Automated version bump and checksum update for v${VERSION}.
-
-cc @cpfarhood" \
+            --body "$BODY" \
             --base main \
             --head "release/v${VERSION}"
           gh pr merge "release/v${VERSION}" --auto --squash --delete-branch