* Update mypy to 1.6.1
* Fix mypy "Source file found twice under different module names" error
* Ignore type of intialized abstract class in tests
* Use more specific type ignore method-assign
* Type ignore for message.get_all
* Remove unused type ignore
* Add SizedBuffer type for xmlrpc.client.Transport subclass
* Add Self type for RequestHandlerClass in test
* Add type ignore for shutil.rmtree onexc handler
* Quote SizedBuffer
* Add news entry
* Remove no longer correct comment
* Update self import
* Also ignore type onerror=handler
* Update news entry
* Update news entry