[Hexagon] Cleanup, remove obsolete comment

Should have been removed as part of
apache#10581.

tests/python/contrib/test_hexagon/test_launcher.py

@@ -32,14 +32,6 @@
 
 from .conftest import requires_hexagon_toolchain
 
-RPC_SERVER_PORT = 7070
-
-# NOTE on server ports:
-# These tests use different port numbers for the RPC server (7070 + ...).
-# The reason is that an RPC session cannot be gracefully closed without
-# triggering TIME_WAIT state on the server socket. This prevents another
-# server to bind to the same port until the wait time elapses.
-
 
 @requires_hexagon_toolchain
 def test_add(hexagon_session):