[CI] Path-gate Rust workspace tests in lint (#34864)

.github/workflows/lint.yml

@@ -13,6 +13,16 @@ jobs:
         with:
           fetch-depth: 0
 
+      - name: Detect Rust workspace changes
+        id: paths
+        uses: dorny/paths-filter@v3
+        with:
+          filters: |
+            rust_workspace:
+              - 'rust/**'
+              - 'proto/sglang/runtime/v1/sglang.proto'
+              - '.github/workflows/lint.yml'
+
       # Fail-fast gate: docs_new/ was renamed to docs/ (#32123). git's rename
       # detection silently re-adds NEW files under docs_new/ on merge without a
       # conflict, which would resurrect the directory. We check the checked-out
@@ -54,6 +64,7 @@ jobs:
       # and a test script is not a build input. Tests take ~1s; the timeout is
       # for a cold cache, which codegens the dependency graph first.
       - name: Run rust/ workspace tests
+        if: steps.paths.outputs.rust_workspace == 'true'
         run: cd rust && timeout 900 cargo test --workspace
 
       - name: Run lychee docs checks (offline references)