fix(streamable-http): reject duplicate request IDs #2420

Job	Run time
checks / pre-commit	33s
checks / readme-snippets	11s
checks / test (3.12, locked, ubuntu-latest)	1m 8s
checks / test (3.11, lowest-direct, windows-latest)	3m 24s
checks / test (3.10, locked, windows-latest)	2m 51s
checks / test (3.10, lowest-direct, ubuntu-latest)	1m 6s
checks / test (3.11, locked, ubuntu-latest)	1m 3s
checks / test (3.11, lowest-direct, ubuntu-latest)	1m 5s
checks / test (3.11, locked, windows-latest)	2m 49s
checks / test (3.12, lowest-direct, ubuntu-latest)	1m 16s
checks / test (3.14, lowest-direct, ubuntu-latest)	1m 46s
checks / test (3.12, locked, windows-latest)	3m 30s
checks / test (3.13, lowest-direct, ubuntu-latest)	1m 1s
checks / test (3.13, lowest-direct, windows-latest)	2m 59s
checks / test (3.14, locked, windows-latest)	3m 27s
checks / test (3.12, lowest-direct, windows-latest)	3m 46s
checks / test (3.14, lowest-direct, windows-latest)	2m 38s
checks / test (3.13, locked, windows-latest)	2m 38s
checks / test (3.14, locked, ubuntu-latest)	2m 31s
checks / test (3.13, locked, ubuntu-latest)	58s
checks / test (3.10, locked, ubuntu-latest)	1m 4s
checks / test (3.10, lowest-direct, windows-latest)	2m 51s
all-green	5s
	44m 40s

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