fix: revert temporarily remove b200 tests (#11515)

.github/workflows/pr-test.yml

@@ -664,34 +664,34 @@ jobs:
           cd test/srt
           python3 run_suite.py --suite per-commit-8-gpu-deepep
 
-  #unit-test-backend-4-gpu-b200:
-  #  needs: [check-changes, unit-test-backend-2-gpu, sgl-kernel-build-wheels]
-  #  if: always() && !failure() && !cancelled() &&
-  #      ((needs.check-changes.outputs.main_package == 'true') || (needs.check-changes.outputs.sgl_kernel == 'true'))
-  #  runs-on: 4-gpu-b200
-  #  strategy:
-  #    fail-fast: false
-  #  steps:
-  #    - name: Checkout code
-  #      uses: actions/checkout@v4
-  #
-  #    - name: Download artifacts
-  #      if: needs.check-changes.outputs.sgl_kernel == 'true'
-  #      uses: actions/download-artifact@v4
-  #      with:
-  #        path: sgl-kernel/dist/
-  #        merge-multiple: true
-  #        pattern: wheel-python3.10-cuda12.9
-  #
-  #    - name: Install dependencies
-  #      run: |
-  #        CUSTOM_BUILD_SGL_KERNEL=${{needs.check-changes.outputs.sgl_kernel}} IS_BLACKWELL=1 bash scripts/ci/ci_install_dependency.sh
-  #
-  #    - name: Run test
-  #      timeout-minutes: 45
-  #      run: |
-  #        cd test/srt
-  #        python3 run_suite.py --suite per-commit-4-gpu-b200 --auto-partition-id 0 --auto-partition-size 1 --timeout-per-file 3600
+  unit-test-backend-4-gpu-b200:
+    needs: [check-changes, unit-test-backend-2-gpu, sgl-kernel-build-wheels]
+    if: always() && !failure() && !cancelled() &&
+        ((needs.check-changes.outputs.main_package == 'true') || (needs.check-changes.outputs.sgl_kernel == 'true'))
+    runs-on: 4-gpu-b200
+    strategy:
+      fail-fast: false
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+  
+      - name: Download artifacts
+        if: needs.check-changes.outputs.sgl_kernel == 'true'
+        uses: actions/download-artifact@v4
+        with:
+          path: sgl-kernel/dist/
+          merge-multiple: true
+          pattern: wheel-python3.10-cuda12.9
+  
+      - name: Install dependencies
+        run: |
+          CUSTOM_BUILD_SGL_KERNEL=${{needs.check-changes.outputs.sgl_kernel}} IS_BLACKWELL=1 bash scripts/ci/ci_install_dependency.sh
+  
+      - name: Run test
+        timeout-minutes: 45
+        run: |
+          cd test/srt
+          python3 run_suite.py --suite per-commit-4-gpu-b200 --auto-partition-id 0 --auto-partition-size 1 --timeout-per-file 3600
 
   pr-test-finish:
     needs: [