ci(release-plz): add a Rust cache step hoping to speed up the job

.github/workflows/release-plz.yml

@@ -20,13 +20,18 @@ jobs:
         with:
           app-id: ${{ secrets.RELEASE_PLZ_GITHUB_APP_ID }}
           private-key: ${{ secrets.RELEASE_PLZ_GITHUB_APP_SECRET }}
+
       - name: Checkout repository
         uses: actions/checkout@v4
         with:
           fetch-depth: 0
           token: ${{ steps.generate-token.outputs.token }}
+
       - name: Install Rust toolchain
         uses: dtolnay/rust-toolchain@stable
+
+      - uses: Swatinem/rust-cache@v2
+
       - name: Run release-plz
         uses: MarcoIeni/release-plz-action@v0.5
         env: