[graingert]

• this helps with no way to explicitly shutdown async generators #1953 because the caller of render_async can ensure they close their async generators, and jinja2 does not introduce new async generators that cannot be explicitly closed

Checklist:

• Add tests that demonstrate the correct behavior of the change. Tests should fail without the change.
• Add or update relevant docs, in the docs folder and in code.
• Add an entry in CHANGES.rst summarizing the change and linking to the issue.
• Add .. versionchanged:: entries in any relevant code docs.
• Run pre-commit hooks and fix any issues.
• Run pytest and tox, no tests failed.

[davidism]

Superseded by #1960