Make client-side cancellation work over the 2026 transports #3355

Job	Run time
checks / readme-snippets	15s
checks / pre-commit	49s
checks / docs	39s
checks / test (3.10, locked, ubuntu-latest)	1m 23s
checks / test (3.10, lowest-direct, ubuntu-latest)	1m 10s
checks / test (3.12, lowest-direct, windows-latest)	1m 46s
checks / test (3.10, lowest-direct, windows-latest)	1m 59s
checks / test (3.11, lowest-direct, windows-latest)	1m 57s
checks / test (3.12, lowest-direct, ubuntu-latest)	1m 24s
checks / test (3.11, lowest-direct, ubuntu-latest)	1m 29s
checks / test (3.10, locked, windows-latest)	2m 0s
checks / test (3.11, locked, ubuntu-latest)	1m 24s
checks / test (3.14, lowest-direct, ubuntu-latest)	1m 16s
checks / test (3.14, locked, ubuntu-latest)	2m 21s
checks / test (3.11, locked, windows-latest)	2m 21s
checks / test (3.12, locked, windows-latest)	2m 5s
checks / test (3.14, locked, windows-latest)	4m 35s
checks / test (3.13, lowest-direct, ubuntu-latest)	1m 22s
checks / test (3.13, locked, windows-latest)	1m 51s
checks / test (3.13, lowest-direct, windows-latest)	1m 53s
checks / test (3.14, lowest-direct, windows-latest)	1m 40s
checks / test (3.13, locked, ubuntu-latest)	1m 15s
checks / test (3.12, locked, ubuntu-latest)	1m 5s
all-green	5s
	38m 4s

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