Update release-plz.yml

Create a relase pr rather than a release.

Author: MidasLamb

.github/workflows/release-plz.yml

@@ -22,6 +22,8 @@ jobs:
         uses: dtolnay/rust-toolchain@stable
       - name: Run release-plz
         uses: MarcoIeni/release-plz-action@v0.5
+        with:
+          command: release-pr
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
           CARGO_REGISTRY_TOKEN: ${{ secrets.CARGO_REGISTRY_TOKEN }}