create rust workspace (#32014)

.github/workflows/lint.yml

@@ -23,6 +23,14 @@ jobs:
           python -m pip install pre-commit
           pre-commit install
 
+      # The clippy-rust-workspace pre-commit hook compiles the rust/ workspace
+      # (debug profile); cache cargo registry + target across runs.
+      - name: Rust cache (rust/ workspace)
+        uses: Swatinem/rust-cache@v2
+        with:
+          workspaces: rust
+          shared-key: "rust-workspace-lint"
+
       - name: Run pre-commit checks
         run: SKIP=no-commit-to-branch pre-commit run --all-files --show-diff-on-failure
 

.github/workflows/pr-test.yml

@@ -309,10 +309,10 @@ jobs:
         timeout-minutes: 10
         run: bash scripts/ci/utils/install_rust_protoc.sh
 
-      - name: Rust cache (sglang-grpc)
+      - name: Rust cache (rust/ workspace)
         uses: Swatinem/rust-cache@v2
         with:
-          workspaces: rust/sglang-grpc
+          workspaces: rust
           shared-key: "sglang-grpc-cpu"
           save-if: ${{ matrix.partition == 0 }}