chore(ci): use env var for cargo token check in release workflow

Author: Akagi201

.github/workflows/release.yml

@@ -12,6 +12,8 @@ jobs:
   release:
     name: Release
     runs-on: ubuntu-latest
+    env:
+      HAS_CARGO_TOKEN: ${{ secrets.CARGO_REGISTRY_TOKEN != '' }}
     steps:
       - name: Checkout
         uses: actions/checkout@v6
@@ -74,7 +76,7 @@ jobs:
           fi
 
       - name: Publish to crates.io
-        if: ${{ secrets.CARGO_REGISTRY_TOKEN != '' && steps.publish-ready.outputs.ready == 'true' }}
+        if: ${{ env.HAS_CARGO_TOKEN == 'true' && steps.publish-ready.outputs.ready == 'true' }}
         run: cargo publish --workspace --locked
         env:
           CARGO_REGISTRY_TOKEN: ${{ secrets.CARGO_REGISTRY_TOKEN }}