Update Python SDK Version to 1.18.0b4 (#1356)

* Update Python SDK Version to 1.18.0b4

* Update setup.py

---------

Co-authored-by: AzureFunctionsPython <[email protected]>

Author: gavin-aguiar

setup.py

@@ -106,7 +106,7 @@
 ]
 
 INSTALL_REQUIRES = [
-    "azure-functions==1.18.0b3",
+    "azure-functions==1.18.0b4",
     "python-dateutil~=2.8.2"
 ]