[core] Remove swift 6 concurrency errors (WIP do not merge) #456

Job	Run time
Semantic Version label check	5s
musl	1m 24s
Unit tests / Construct unit test matrix	2s
Integration Tests / Test archive plugin	2m 25s
Integration Tests / No dependencies on Foundation	1m 39s
Integration Tests / Test Examples/APIGateway on 6.0.1-amazonlinux2	1m 26s
Integration Tests / Test Examples/APIGateway+LambdaAuthorizer on 6.0.1-amazonlinux2	1m 26s
Soundness / API breakage check	1m 44s
Soundness / Broken symlinks check	3s
Integration Tests / Test Examples/BackgroundTasks on 6.0.1-amazonlinux2	1m 17s
Integration Tests / Test Examples/HelloJSON on 6.0.1-amazonlinux2	1m 14s
Integration Tests / Test Examples/HelloWorld on 6.0.1-amazonlinux2	1m 14s
Soundness / Documentation check	1m 34s
Soundness / Format check	34s
Integration Tests / Test Examples/S3_AWSSDK on 6.0.1-amazonlinux2	4m 21s
Integration Tests / Test Examples/S3_Soto on 6.0.1-amazonlinux2	4m 50s
Soundness / License headers check	4s
Integration Tests / Test Examples/Streaming on 6.0.1-amazonlinux2	1m 16s
Integration Tests / Test Examples/Testing on 6.0.1-amazonlinux2	1m 21s
Soundness / Python lint check	8s
Integration Tests / Test Examples/Tutorial on 6.0.1-amazonlinux2	1m 15s
Soundness / Shell check	32s
Soundness / Unacceptable language check	3s
Soundness / YAML lint check	3s
Swift 6 Language Mode / Swift 6 language mode	1m 14s
Unit tests / Unit tests / Linux (6.0)	1m 18s
Unit tests / Unit tests / Linux (nightly-6.0)	1m 32s
Unit tests / Unit tests / Linux (nightly-main)	1m 35s
	35m 39s

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