remove legacy stage

Author: tqchen

Jenkinsfile

@@ -310,17 +310,6 @@ stage('Integration Test') {
       }
     }
   },
-  'legacy: GPU': {
-    node('GPU') {
-      ws(per_exec_ws("tvm/legacy-python-gpu")) {
-        init_git()
-        unpack_lib('gpu', tvm_multilib)
-        timeout(time: max_time, unit: 'MINUTES') {
-          sh "${docker_run} ${ci_gpu} ./tests/scripts/task_python_legacy.sh"
-        }
-      }
-    }
-  },
   'docs: GPU': {
     node('GPU') {
       ws(per_exec_ws("tvm/docs-python-gpu")) {