Make asyncio eager task factory default

[Rosuav (Chris Angelico)]

@guido

But I think it’s too soon to turn it on by default in 3.14. I would want a super simple way for users to decide whether to use lazy or eager, probably at event loop creation (maybe a new flag to asyncio.run()?)flag,

The docs currently recommend setting the task factory. How would such a super-simple way interact with other task factories?

(I’ve never used custom task types so I have no idea what the consequences would be. All I know is, that one-liner from the docs does indeed make Python behave the same way other languages do.)