Rename GPU GitHub runner to avoid version confusion

Author: sutaakar

.github/workflows/e2e_tests.yaml

@@ -27,7 +27,7 @@ concurrency:
 jobs:
   kubernetes-e2e:
 
-    runs-on: ubuntu-20.04-4core-gpu
+    runs-on: gpu-t4-4-core
 
     steps:
       - name: Checkout code