Wait for `closeFuture` instead of close promise in `NIOAsyncChannel`'s `executeThenClose` #1123

Job	Run time
Construct integration test matrix	3s
Vsock tests	1m 57s
Benchmarks / Construct Benchmarks matrix	3s
Cxx interop / Construct Cxx interop matrix	7s
Unit tests / Construct unit test matrix	3s
Soundness / API breakage check	2m 5s
Soundness / Broken symlinks check	5s
Soundness / Documentation check	2m 11s
Soundness / Format check	48s
Soundness / License headers check	9s
Soundness / Python lint check	5s
Soundness / Shell check	36s
Soundness / Unacceptable language check	3s
Soundness / YAML lint check	5s
Benchmarks / Benchmarks / Linux (5.9)	5m 28s
Benchmarks / Benchmarks / Linux (5.10)	5m 6s
Benchmarks / Benchmarks / Linux (6.0)	5m 16s
Integration tests / Linux (5.9)	15m 31s
Benchmarks / Benchmarks / Linux (nightly-6.0)	6m 46s
Integration tests / Linux (5.10)	14m 17s
Benchmarks / Benchmarks / Linux (nightly-main)	4m 27s
Integration tests / Linux (6.0)	16m 31s
Integration tests / Linux (nightly-6.0)	16m 40s
Integration tests / Linux (nightly-main)	16m 51s
Unit tests / Unit tests / Linux (5.9)	3m 52s
Unit tests / Unit tests / Linux (5.10)	3m 45s
Unit tests / Unit tests / Linux (6.0)	4m 7s
Unit tests / Unit tests / Linux (nightly-6.0)	4m 42s
Unit tests / Unit tests / Linux (nightly-main)	4m 40s
Cxx interop / Cxx interop / Linux (5.9)	1m 10s
Cxx interop / Cxx interop / Linux (5.10)	1m 12s
Cxx interop / Cxx interop / Linux (6.0)	1m 27s
Cxx interop / Cxx interop / Linux (nightly-6.0)	1m 31s
Cxx interop / Cxx interop / Linux (nightly-main)	1m 41s
	2h 23m 20s

Provide feedback