chore(deps): update actions/checkout action to v6 (#648)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

.github/workflows/publish.yaml

@@ -15,7 +15,7 @@ jobs:
           token: ${{ secrets.PORTER_GITHUB_TOKEN }}
 
       - name: Checkout
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
         if: ${{ steps.release.outputs.release_created }}
 
       - name: Build and publish to GitHub Package