ci: check if Cargo.lock is up-to-date

Author: weihanglo

.github/workflows/main.yml

@@ -37,6 +37,14 @@ jobs:
       # TODO: check every members
       - run: cargo clippy -p cargo --lib --no-deps -- -D warnings
 
+  # Ensure Cargo.lock is up-to-date
+  lockfile:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+      - run: rustup update stable && rustup default stable
+      - run: cargo update -p cargo --locked
+
   test:
     runs-on: ${{ matrix.os }}
     env: