ci: use custom rust toolchain in release process

.github/workflows/release.yaml

@@ -7,9 +7,24 @@ on:
 
 jobs:
 
+  rust-toolchain:
+    runs-on: ubuntu-latest
+    outputs:
+      version: ${{ steps.rust-toolchain.outputs.version }}
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Extract rust toolchain version
+        id: rust-toolchain
+        run: echo "version=$(cat rust-toolchain)" >> "${GITHUB_OUTPUT}"
+
   release:
+    needs: rust-toolchain
     uses: matter-labs/zksync-ci-common/.github/workflows/release-plz.yaml@v1
     secrets:
       gh_token: ${{ secrets.RELEASE_TOKEN }}
       cargo_registry_token: ${{ secrets.CRATES_IO_TOKEN }}
       slack_webhook: ${{ secrets.SLACK_WEBHOOK_RELEASES }}
+    with:
+      rust-toolchain: ${{ needs.rust-toolchain-version.outputs.version }}