Fix routing.get_name() not to assume all routines have __name__ (#2648)

Fix `routing.get_name()` to use the `__name__` attribute only if it is
actually present, rather than assuming that all routine and class types
have it, and use the fallback to class name otherwise.  This is
necessary for `functools.partial()` that doesn't have a `__name__`
attribute, but is recognized as a routine starting with Python 3.13.0b3.
Since for older versions of Python, it would have used the fallback
anyway, this doesn't really change the behavior there.

Fixes #2638

Author: mgorny

starlette/routing.py

@@ -99,9 +99,7 @@ async def app(scope: Scope, receive: Receive, send: Send) -> None:
 
 
 def get_name(endpoint: typing.Callable[..., typing.Any]) -> str:
-    if inspect.isroutine(endpoint) or inspect.isclass(endpoint):
-        return endpoint.__name__
-    return endpoint.__class__.__name__
+    return getattr(endpoint, "__name__", endpoint.__class__.__name__)
 
 
 def replace_params(