Propagate contextvars.Context through anyio streams without modifying SessionMessage #1719

Job	Run time
checks / readme-snippets	14s
checks / test (3.11, lowest-direct, windows-latest)	2m 16s
checks / test (3.10, lowest-direct, ubuntu-latest)	48s
checks / test (3.14, lowest-direct, windows-latest)	2m 14s
checks / test (3.12, locked, ubuntu-latest)	55s
checks / test (3.10, lowest-direct, windows-latest)	2m 11s
checks / test (3.14, locked, ubuntu-latest)	2m 17s
checks / test (3.11, locked, ubuntu-latest)	51s
checks / test (3.14, lowest-direct, ubuntu-latest)	1m 14s
checks / test (3.12, lowest-direct, ubuntu-latest)	57s
checks / test (3.11, locked, windows-latest)	2m 24s
checks / test (3.13, lowest-direct, windows-latest)	3m 11s
checks / test (3.13, locked, ubuntu-latest)	46s
checks / pre-commit	31s
checks / test (3.10, locked, ubuntu-latest)	49s
checks / test (3.13, locked, windows-latest)	2m 46s
checks / test (3.13, lowest-direct, ubuntu-latest)	55s
checks / test (3.11, lowest-direct, ubuntu-latest)	52s
checks / test (3.12, locked, windows-latest)	3m 45s
checks / test (3.12, lowest-direct, windows-latest)	3m 29s
checks / test (3.14, locked, windows-latest)	3m 22s
checks / test (3.10, locked, windows-latest)	2m 7s
all-green	3s
	38m 57s

Provide feedback