[skip ci] Update pymilvus-orm version in requirements (#6279)

* [skip ci] Update pymilvus-orm version in requirements
Signed-off-by: Nyanliang567 <yanliang.qiao@zilliz.com>

* [skip ci] Update pymilvus-orm version in requirements
Signed-off-by: Nyanliang567 <yanliang.qiao@zilliz.com>

tests20/python_client/requirements.txt

@@ -12,7 +12,7 @@ pytest-print==0.2.1
 pytest-level==0.1.1
 pytest-xdist==2.2.1
 pytest-parallel
-pymilvus-orm==2.0a1.dev62
+pymilvus-orm==2.0.0rc2.dev16
 pytest-rerunfailures==9.1.1
 git+https://github.com/Projectplace/pytest-tags
 ndg-httpsclient