Wait for `closeFuture` instead of close promise in `NIOAsyncChannel`'s `executeThenClose` #1120

Job	Run time
Construct integration test matrix	2s
Vsock tests	2m 18s
Benchmarks / Construct Benchmarks matrix	3s
Cxx interop / Construct Cxx interop matrix	3s
Unit tests / Construct unit test matrix	5s
Soundness / Broken symlinks check	2s
Soundness / Documentation check	1m 20s
Soundness / API breakage check	2m 0s
Soundness / License headers check	10s
Soundness / Format check	48s
Soundness / Python lint check	5s
Soundness / Shell check	36s
Soundness / Unacceptable language check	2s
Soundness / YAML lint check	6s
Integration tests / Linux (5.9)	15m 34s
Integration tests / Linux (5.10)	14m 12s
Integration tests / Linux (6.0)	16m 13s
Integration tests / Linux (nightly-6.0)	16m 19s
Integration tests / Linux (nightly-main)	16m 42s
Benchmarks / Benchmarks / Linux (5.9)	5m 19s
Benchmarks / Benchmarks / Linux (5.10)	4m 51s
Benchmarks / Benchmarks / Linux (6.0)	5m 17s
Benchmarks / Benchmarks / Linux (nightly-6.0)	5m 49s
Benchmarks / Benchmarks / Linux (nightly-main)	4m 28s
Cxx interop / Cxx interop / Linux (5.9)	1m 7s
Cxx interop / Cxx interop / Linux (5.10)	1m 11s
Cxx interop / Cxx interop / Linux (6.0)	1m 16s
Cxx interop / Cxx interop / Linux (nightly-6.0)	1m 33s
Cxx interop / Cxx interop / Linux (nightly-main)	1m 36s
Unit tests / Unit tests / Linux (5.9)	3m 43s
Unit tests / Unit tests / Linux (5.10)	3m 39s
Unit tests / Unit tests / Linux (6.0)	4m 4s
Unit tests / Unit tests / Linux (nightly-6.0)	4m 37s
Unit tests / Unit tests / Linux (nightly-main)	4m 32s
	2h 19m 42s

Provide feedback