`ruff-ecosystem` CLI crashes on Python 3.14

[dylwil3]

This is not a big deal since I can just install the tool with 3.13, but this line

ruff/python/ruff-ecosystem/ruff_ecosystem/cli.py

Line 90 in 3c229ae

loop = asyncio.get_event_loop()

causes a crash on Python 3.14 when there is not yet an event loop (see https://docs.python.org/3/library/asyncio-eventloop.html#asyncio.get_event_loop).