maybe it's as simple as this?

Author: Rich-Harris

.github/workflows/docs-preview-create.yml

@@ -16,12 +16,11 @@ jobs:
           cache: pnpm
       - run: pnpm install --frozen-lockfile
 
+      - name: Checkout
+        run: git checkout -B refs/heads/sync/${{ github.event.client_payload.package }}/${{ github.event.client_payload.owner }}/${{ github.event.client_payload.branch }}
+
       - name: Sync
-        run: cd apps/svelte.dev && pnpm sync-docs --owner="${{ github.event.client_payload.owner }}" -p "${{ github.event.client_payload.package }}#${{ github.event.client_payload.branch }}""
+        run: cd apps/svelte.dev && pnpm sync-docs --owner="${{ github.event.client_payload.owner }}" -p "${{ github.event.client_payload.package }}#${{ github.event.client_payload.branch }}"
 
-      - name: Create branch
-        uses: peterjgrainger/[email protected]
-        env:
-          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
-        with:
-          branch: refs/heads/sync/${{ github.event.client_payload.package }}/${{ github.event.client_payload.owner }}/${{ github.event.client_payload.branch }}
+      - name: Push
+        run: git add -A && git commit -m "sync docs" && git push -u origin sync/${{ github.event.client_payload.package }}/${{ github.event.client_payload.owner }}/${{ github.event.client_payload.branch }}