fix: raise UserWarning when trying to wrap generators with container_context

[xelandernt]

Makes the following raise a UserWarning

@container_context(...)
async def my_generator(...):
    yield

Since @container_context() does not support generators.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.

Flag	Coverage Δ
unittests	100.00% <100.00%> (ø)

Flags with carried forward coverage won't be shown. Click here to find out more.

Files with missing lines	Coverage Δ
tests/providers/test_context_resources.py	100.00% <100.00%> (ø)
that_depends/providers/context_resources.py	100.00% <100.00%> (ø)

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.