dateutil is install required as in setting multi set-cookie headers chg (#1021)

Co-authored-by: peterstone2017 <yunchuwang5@gmail.com>

setup.py

@@ -105,13 +105,13 @@ INSTALL_REQUIRES = [
     "grpcio~=1.43.0",
     "grpcio-tools~=1.43.0",
     "protobuf~=3.19.3",
-    'azure-functions==1.11.1'
+    "azure-functions==1.11.1",
+    "python-dateutil~=2.8.2"
 ]
 
 EXTRA_REQUIRES = {
     "dev": [
         "azure-eventhub~=5.7.0",  # Used for EventHub E2E tests
-        "python-dateutil~=2.8.2",
         "flask",
         "fastapi",
         "pydantic",