Cleanup ruff style complaint

Interestingly, ruff and µsort have different opinions on how headers
should be sorted. Guess one has to win out over time (µsort prefers to
have blank lines between regular "import" lines and "from X import Y"
lines).

eventkit/util.py

@@ -1,7 +1,6 @@
 import asyncio
 import datetime as dt
 import functools
-
 from typing import AsyncIterator