PTB's HTTPXRequest/BaseRequest use __slots__. On Python 3.13 their
instances no longer carry a __dict__, so the getUpdates progress
instrumentation's `request.do_request = wrapper` monkey-patch raises
`AttributeError: 'HTTPXRequest' object attribute 'do_request' is
read-only`, failing every Telegram connect (#64482). It only worked on
Python 3.12, where the instance still had a __dict__ — the Docker image
ships Python 3.13, so the release broke Telegram outright.
Re-tag the request to a thin `__slots__ = ()` subclass that overrides
do_request instead of mutating the instance. This preserves the exact
progress-observation semantics, works on both 3.12 and 3.13, and covers
the real request and the test doubles alike.