remove unnecessary use of generators for session retrieval

[rchl]

Use of generators for retrieving the session is IMO completely unnecessary (correct me if I'm missing something).

1. This is not an expensive operation that would benefit from being interrupted early. Getting all sessions and returning a list is not gonna be slower. It will potentially even be faster as I imagine that generators have some overhead.
2. Passing generators around can lead to errors or at least confusion since the values can only be retrieved once from it. In cases like

   LSP/plugin/core/registry.py

   Lines 24 to 33 in 603632e

   	def best_session(view: sublime.View, sessions: Iterable[Session], point: int | None = None) -> Session | None:
   	if point is None:
   	try:
   	point = view.sel()[0].b
   	except IndexError:
   	return None
   	try:
   	return max(sessions, key=lambda s: view.score_selector(point, s.config.priority_selector)) # type: ignore
   	except ValueError:
   	return None

   where we pass generators and disguise it as Iterable[Session], there is no way of knowing that the code will fail if trying to iterate sessions twice.

[jwortmann]

I think this change for the parameter type is unnecessary here because list is still an Iterable, so this just makes the function more restrictive where it doesn't need to be. And Iterable would be more inline with the usage in max, which takes an iterable https://docs.python.org/3/library/functions.html#max

But frankly it doesn't really matter and I think nobody payed much intention of this throughout the rest of the code base.