Deflake the issue-1363 tests: wait for lifespan startup instead of sleeping #2714

Job	Run time
checks / pre-commit	33s
checks / readme-snippets	12s
checks / test (3.10, locked, ubuntu-latest)	46s
checks / test (3.11, lowest-direct, ubuntu-latest)	57s
checks / test (3.10, locked, windows-latest)	1m 21s
checks / test (3.14, lowest-direct, ubuntu-latest)	55s
checks / test (3.11, lowest-direct, windows-latest)	1m 23s
checks / test (3.12, lowest-direct, ubuntu-latest)	1m 28s
checks / test (3.12, lowest-direct, windows-latest)	1m 28s
checks / test (3.13, lowest-direct, windows-latest)	1m 28s
checks / test (3.13, locked, ubuntu-latest)	50s
checks / test (3.11, locked, windows-latest)	1m 18s
checks / test (3.12, locked, windows-latest)	1m 24s
checks / test (3.11, locked, ubuntu-latest)	54s
checks / test (3.10, lowest-direct, windows-latest)	1m 28s
checks / test (3.12, locked, ubuntu-latest)	59s
checks / test (3.10, lowest-direct, ubuntu-latest)	1m 12s
checks / test (3.13, locked, windows-latest)	1m 16s
checks / test (3.14, locked, windows-latest)	2m 35s
checks / test (3.14, locked, ubuntu-latest)	2m 1s
checks / test (3.14, lowest-direct, windows-latest)	1m 31s
checks / test (3.13, lowest-direct, ubuntu-latest)	57s
all-green	4s
	27m 0s

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