[Cosmos] set startup to false on any refresh (#40203)

* set startup to false on any refresh

* Update CHANGELOG.md

* Update _global_endpoint_manager_async.py

* Update _global_endpoint_manager_async.py

Author: simorenoh

sdk/cosmos/azure-cosmos/CHANGELOG.md

@@ -7,6 +7,7 @@
 #### Breaking Changes
 
 #### Bugs Fixed
+* Fixed too many health checks happening when skipping the recommended client startup. See [PR 40203](https://github.com/Azure/azure-sdk-for-python/pull/40203).
 
 #### Other Changes
 

sdk/cosmos/azure-cosmos/azure/cosmos/aio/_global_endpoint_manager_async.py

@@ -135,6 +135,7 @@ async def _refresh_endpoint_list_private(self, database_account=None, **kwargs):
                 else:
                     # on startup do this in foreground
                     await self._endpoints_health_check(**kwargs)
+                    self.startup = False
 
     async def _endpoints_health_check(self, **kwargs):
         """Gets the database account for each endpoint.