ci: add rust-toolchain

.github/workflows/scheduled_lints.yml

@@ -19,6 +19,7 @@ jobs:
           git checkout -f $(git -c user.name=x -c user.email=x@x commit-tree $(git hash-object -t tree /dev/null) < /dev/null) || :
       - name: Clone the repository
         uses: actions/checkout@v4
+      - uses: actions-rust-lang/setup-rust-toolchain@v1
       - name: Cargo Cache
         uses: actions/cache@v4
         with: