Export runner labels via env var (#13018)

.github/workflows/nightly-test-b200.yml

@@ -37,6 +37,8 @@ jobs:
     if: github.repository == 'sgl-project/sglang'
     runs-on: 8-gpu-b200
     continue-on-error: true
+    env:
+      RUNNER_LABELS: 8-gpu-b200
     steps:
       - name: Checkout code
         uses: actions/checkout@v4

.github/workflows/nightly-test.yml

@@ -151,6 +151,8 @@ jobs:
     if: github.repository == 'sgl-project/sglang'
     runs-on: 8-gpu-h200
     continue-on-error: true
+    env:
+      RUNNER_LABELS: 8-gpu-h200
     steps:
       - name: Checkout code
         uses: actions/checkout@v4

.github/workflows/pr-test.yml

@@ -467,6 +467,8 @@ jobs:
     if: always() && !failure() && !cancelled() &&
       ((needs.check-changes.outputs.main_package == 'true') || (needs.check-changes.outputs.sgl_kernel == 'true'))
     runs-on: 8-gpu-h200
+    env:
+      RUNNER_LABELS: 8-gpu-h200
     strategy:
       fail-fast: false
       matrix:
@@ -818,6 +820,8 @@ jobs:
     if: always() && !failure() && !cancelled() &&
       ((needs.check-changes.outputs.main_package == 'true') || (needs.check-changes.outputs.sgl_kernel == 'true'))
     runs-on: 8-gpu-h200
+    env:
+      RUNNER_LABELS: 8-gpu-h200
     steps:
       - name: Checkout code
         uses: actions/checkout@v4
@@ -845,6 +849,8 @@ jobs:
     if: always() && !failure() && !cancelled() &&
       ((needs.check-changes.outputs.main_package == 'true') || (needs.check-changes.outputs.sgl_kernel == 'true'))
     runs-on: 8-gpu-h200
+    env:
+      RUNNER_LABELS: 8-gpu-h200
     steps:
       - name: Checkout code
         uses: actions/checkout@v4