fix type of _SansIOHTTPPolicyRunner (Azure#24932)

* fix type of _SansIOHTTPPolicyRunner

* update changelog

Author: xiangyan99

sdk/core/azure-core/CHANGELOG.md

@@ -8,6 +8,8 @@
 
 ### Bugs Fixed
 
+- Fixed the bug that azure-core could not be imported under Python 3.11.0b3  #24928
+
 ### Other Changes
 
 ## 1.24.1 (2022-06-01)

sdk/core/azure-core/azure/core/pipeline/_base.py

@@ -43,7 +43,7 @@
 PoliciesType = List[Union[HTTPPolicy, SansIOHTTPPolicy]]
 
 
-class _SansIOHTTPPolicyRunner(HTTPPolicy, Generic[HTTPRequestType, HTTPResponseType]):
+class _SansIOHTTPPolicyRunner(HTTPPolicy):
     """Sync implementation of the SansIO policy.
 
     Modifies the request and sends to the next policy in the chain.