Revert "remove shanghai assignee during 5.1 holiday" (#9354)

* Revert "remove shanghai assignee during 5.1 holiday (#9254)"

This reverts commit e4fd866.

* remove Allen as reviewer in May as requested

Author: akning-ms

.github/assignment.yml

@@ -135,5 +135,20 @@
     paths:
       - "**"
     reviewers:
+      - yungezz
+      - zikalino
+      - erich-wang
+      - NullMDR
+      - raych1
+      - lirenhe
+      - weidongxu-microsoft
+      - ArcturusZhang
+      - xccc-msft
+      - ChenTanyi
+      - fengzhou-msft
+      - njuCZ
+      - akning-ms
       - markcowl
-      - allenjzhang
+      - leni-msft
+      - qianwens
+      - ruowan