Markdownlint Action is running twice

I noticed that the markdownlint GitHub Action that we have is running twice on the same PR.
It is mostly a cosmetic problem and it also might be a bit confusing for people.

I know that we could prevent it by limiting the action workflow execution to pushes to master like in this GHA configuration. However that seems to have other undesirable consequences.

I wonder if there is some way to do this?

Example:

See the bottom of https://github.com/InnerSourceCommons/InnerSourcePatterns/pull/261/

Screenshot:

GitHub Actions の workflow 設定を調べ、リンクされた .github/workflows/lint-patterns.yml の例と比較してから、pull request #261 に表示されている重複実行を確認します。markdownlint が pull request ごとに 1 回実行され、push 時に必要な workflow の動作が失われなければ完了です。