fix(streamable-http): expose session_idle_timeout and pause idle reaping during active requests #1898

Job	Run time
checks / pre-commit	37s
checks / readme-snippets	11s
checks / test (3.11, lowest-direct, windows-latest)	2m 50s
checks / test (3.11, lowest-direct, ubuntu-latest)	55s
checks / test (3.10, locked, windows-latest)	2m 43s
checks / test (3.12, locked, ubuntu-latest)	58s
checks / test (3.13, lowest-direct, ubuntu-latest)	56s
checks / test (3.11, locked, windows-latest)	3m 1s
checks / test (3.13, locked, windows-latest)	2m 39s
checks / test (3.10, lowest-direct, windows-latest)	2m 35s
checks / test (3.14, lowest-direct, windows-latest)	2m 22s
checks / test (3.13, lowest-direct, windows-latest)	2m 43s
checks / test (3.14, lowest-direct, ubuntu-latest)	1m 22s
checks / test (3.14, locked, ubuntu-latest)	2m 24s
checks / test (3.10, locked, ubuntu-latest)	53s
checks / test (3.13, locked, ubuntu-latest)	50s
checks / test (3.11, locked, ubuntu-latest)	49s
checks / test (3.10, lowest-direct, ubuntu-latest)	56s
checks / test (3.12, lowest-direct, windows-latest)	3m 49s
checks / test (3.12, lowest-direct, ubuntu-latest)	58s
checks / test (3.12, locked, windows-latest)	3m 10s
checks / test (3.14, locked, windows-latest)	2m 56s
all-green	4s
	40m 41s

Provide feedback