Adding nightly tests as release guard for bot bump workflows (#13655)

.github/workflows/nightly-test.yml

@@ -9,6 +9,13 @@ on:
     paths:
       - "python/sglang/version.py"
   workflow_dispatch:
+  workflow_call:
+    inputs:
+      ref:
+        description: 'Git ref (branch, tag, or SHA) to test. If not provided, uses the default branch.'
+        required: false
+        type: string
+        default: ''
 
 concurrency:
   group: nightly-test-${{ github.ref }}
@@ -21,6 +28,8 @@ jobs:
     steps:
       - name: Checkout code
         uses: actions/checkout@v4
+        with:
+          ref: ${{ inputs.ref || github.ref }}
 
       - name: Install dependencies
         run: |
@@ -38,6 +47,8 @@ jobs:
     steps:
       - name: Checkout code
         uses: actions/checkout@v4
+        with:
+          ref: ${{ inputs.ref || github.ref }}
 
       - name: Install dependencies
         run: |
@@ -67,6 +78,8 @@ jobs:
     steps:
       - name: Checkout code
         uses: actions/checkout@v4
+        with:
+          ref: ${{ inputs.ref || github.ref }}
 
       - name: Install dependencies
         run: |
@@ -84,6 +97,8 @@ jobs:
     steps:
       - name: Checkout code
         uses: actions/checkout@v4
+        with:
+          ref: ${{ inputs.ref || github.ref }}
 
       - name: Install dependencies
         run: |
@@ -116,6 +131,8 @@ jobs:
     steps:
       - name: Checkout code
         uses: actions/checkout@v4
+        with:
+          ref: ${{ inputs.ref || github.ref }}
 
       - name: Install dependencies
         run: |
@@ -133,6 +150,8 @@ jobs:
     steps:
       - name: Checkout code
         uses: actions/checkout@v4
+        with:
+          ref: ${{ inputs.ref || github.ref }}
 
       - name: Install dependencies
         run: |
@@ -152,6 +171,8 @@ jobs:
     steps:
       - name: Checkout code
         uses: actions/checkout@v4
+        with:
+          ref: ${{ inputs.ref || github.ref }}
 
       - name: Install dependencies
         run: |
@@ -171,6 +192,8 @@ jobs:
     steps:
       - name: Checkout code
         uses: actions/checkout@v4
+        with:
+          ref: ${{ inputs.ref || github.ref }}
 
       - name: Install dependencies
         run: |
@@ -192,6 +215,8 @@ jobs:
     steps:
       - name: Checkout code
         uses: actions/checkout@v4
+        with:
+          ref: ${{ inputs.ref || github.ref }}
 
       - name: Install dependencies
         run: |