Update peter-evans/create-pull-request action to v6 (#1748)

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

Author: renovate[bot]

.github/workflows/preview-embroider-upgrade.yml

@@ -24,7 +24,7 @@ jobs:
       - uses: wyvox/action-setup-pnpm@v3
       - run: npx ember-apply@latest unstable-embroider
       - run: pnpm install --fix-lockfile --frozen-lockfile=false
-      - uses: peter-evans/create-pull-request@v5
+      - uses: peter-evans/create-pull-request@v6
         with:
           # A PAT is required to trigger further workflows
           token: ${{ secrets.WORKFLOW_TOKEN }}