The telemetry write budget needs asyncio.timeout, whose uncancel accounting
was only fixed after 3.11.1 — pinning the floor at 3.12 removes that hazard
instead of working around it.
Raising ruff's target-version turns on UP047, so gather_bounded,
_anext_within and stream_with_liveness_timeouts move to def f[T](...) and
the two module-level TypeVars go away. That syntax is a SyntaxError on
3.11, so it can only land together with the version bump.
iomgaa