Propagate contextvars through anyio streams #667

Job	Run time
checks / readme-snippets	12s
checks / test (3.10, locked, windows-latest)	2m 56s
checks / test (3.10, lowest-direct, windows-latest)	4m 29s
checks / test (3.11, lowest-direct, windows-latest)	2m 40s
checks / test (3.10, lowest-direct, ubuntu-latest)	44s
checks / test (3.14, locked, windows-latest)	2m 57s
checks / test (3.14, lowest-direct, ubuntu-latest)	1m 7s
checks / pre-commit	48s
checks / test (3.12, locked, ubuntu-latest)	56s
checks / test (3.14, locked, ubuntu-latest)	2m 18s
checks / test (3.11, locked, ubuntu-latest)	48s
checks / test (3.13, lowest-direct, windows-latest)	2m 39s
checks / test (3.12, lowest-direct, ubuntu-latest)	52s
checks / test (3.11, lowest-direct, ubuntu-latest)	44s
checks / test (3.14, lowest-direct, windows-latest)	2m 8s
checks / test (3.13, lowest-direct, ubuntu-latest)	47s
checks / test (3.12, lowest-direct, windows-latest)	3m 43s
checks / test (3.13, locked, windows-latest)	2m 28s
checks / test (3.10, locked, ubuntu-latest)	55s
checks / test (3.13, locked, ubuntu-latest)	48s
checks / test (3.11, locked, windows-latest)	2m 35s
checks / test (3.12, locked, windows-latest)	3m 22s
all-green	6s
	41m 2s

Provide feedback