Get NIOEmbedded clean under strict concurrency #1110

Job	Run time
Construct integration test matrix	10s
Vsock tests	2m 32s
Unit tests / Construct unit test matrix	5s
Benchmarks / Construct Benchmarks matrix	10s
Cxx interop / Construct Cxx interop matrix	14s
Soundness / API breakage check	2m 5s
Soundness / Documentation check	2m 12s
Soundness / Broken symlinks check	4s
Soundness / License headers check	15s
Soundness / Format check	1m 21s
Soundness / Shell check	1m 5s
Soundness / Unacceptable language check	6s
Soundness / YAML lint check	7s
Soundness / Python lint check	7s
Unit tests / Unit tests / Linux (5.9)	4m 2s
Unit tests / Unit tests / Linux (5.10)	3m 46s
Unit tests / Unit tests / Linux (6.0)	1m 10s
Unit tests / Unit tests / Linux (nightly-6.0)	1m 10s
Unit tests / Unit tests / Linux (nightly-main)	4m 38s
Integration tests / Linux (5.9)	15m 41s
Integration tests / Linux (5.10)	14m 10s
Integration tests / Linux (6.0)	16m 31s
Integration tests / Linux (nightly-6.0)	16m 29s
Integration tests / Linux (nightly-main)	16m 53s
Benchmarks / Benchmarks / Linux (5.9)	5m 36s
Benchmarks / Benchmarks / Linux (5.10)	5m 6s
Benchmarks / Benchmarks / Linux (6.0)	5m 34s
Benchmarks / Benchmarks / Linux (nightly-6.0)	5m 55s
Benchmarks / Benchmarks / Linux (nightly-main)	4m 31s
Cxx interop / Cxx interop / Linux (5.9)	1m 14s
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 47s
Cxx interop / Cxx interop / Linux (nightly-main)	1m 45s
	2h 18m 58s

Provide feedback