PEP 828: add synchonous delegation recipe

[graingert]

It's technically incorrect to yield multiple times from inside a structured concurrency context: it's only correct to yield once in that context inside an async generator function decorated with @asynccontextmanager (See PEP 789), therefore the issues as stated with synchronous delegation are incorrect so I removed that text.

Instead keep the note about the complexity and include a recipe on how users can achieve this themselves without adding extra complexity to the PEP 828 implementation, with the hope this recipe can be added to the python docs in the implementation PR

[read-the-docs-community]

Documentation build overview

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2 files changed

± pep-0764/index.html
± pep-0828/index.html