Remove un-necessary socket requirements in async tests

[graingert]

Proposal:

the builtins async tests should run coroutines using coro.send(None) because they don't need an async framework to run. This would remove asyncio from the tests and support running on emscripten/wasi

Has this already been discussed elsewhere?

No response given

Links to previous discussion of this feature:

No response

Linked PRs

• gh-128404: remove asyncio from test_builtin #128403
• gh-128404: remove asyncio from test_sys_settrace #128435
• gh-128404: remove asyncio from test_type_params #128436
• gh-128404: split test_asyncgen.py into tests that require a working socket and tests that do not #128443

[Eclips4]

@graingert Are there many other tests that rely on the asyncio framework that in fact shouldn't rely on it?
If so, let's reuse this issue for them.

[graingert]

I think there's only 3-4 files left.

The last ones I want to touch are test_coroutine.py and test_asyncgens.py because they need a bit of thought. I'd like them split into using framework free code to test the object, and tests that test how asyncio interact with the object moved into test_asyncio. This will involve some duplication I think.

[Eclips4]

Let's now use this issue, and later create issues for test_coroutine & test_asyncgens.

[graingert]

I've gone with this issue currently, for test_asyngens as it's currently a relatively minor rearrangement to start with. I'll do another issue for duplicating auditing the tests that still use asyncio.run/loop.run_until_complete and creating tests that work on wasi etc, while keeping the tests that verify the asyncio integration