chore: Add 'Cancel Previous Runs' step

Author: MichaelDeBoey

.github/workflows/validate.yml

@@ -21,6 +21,11 @@ jobs:
         react: [latest, next, experimental]
     runs-on: ubuntu-latest
     steps:
+      - name: 🛑 Cancel Previous Runs
+        uses: styfle/[email protected]
+        with:
+          access_token: ${{ secrets.GITHUB_TOKEN }}
+
       - name: ⬇️ Checkout repo
         uses: actions/checkout@v2