[CI] Self-scheduled runner also pins torch (#6332)

.github/workflows/self-scheduled.yml

@@ -32,7 +32,8 @@ jobs:
       run: |
         source .env/bin/activate
         pip install --upgrade pip
-        pip install .[sklearn,torch,testing]
+        pip install torch!=1.6.0 --no-cache-dir
+        pip install .[sklearn,testing]
 
     - name: Are GPUs recognized by our DL frameworks
       run: |