Fix concurrency warnings in AsyncProcess #86

Job	Run time
Test / macOS (Xcode 26.0 - sequoia - ARM64)	3m 39s
Test / iOS (Build Only, Xcode 26.0 - sequoia - ARM64)	3m 53s
Test / Linux (nightly-main - noble)	10m 47s
Test / Windows (nightly-main - windows-2022)	26m 46s
Test / Linux (nightly-main - bookworm)	8m 41s
Test / Linux (nightly-main - rhel-ubi9)	9m 53s
Test / Linux (nightly-main - jammy)	10m 0s
Test / Linux (nightly-main - amazonlinux2)	10m 24s
Test / Static Linux Swift SDK Build (${{ matrix.swift_version }} - ${{ matrix.os_version }})	-1s
Soundness / Documentation check	37s
Test / Swift SDK for Android Build (${{ matrix.swift_version }} - ${{ matrix.os_version }} - NDK ${{ matrix.ndk_version }})	-1s
Test / Embedded Swift SDK for Wasm Build (${{ matrix.swift_version }} - ${{ matrix.os_version }})	-1s
Soundness / YAML lint check	9s
Soundness / License headers check	-1s
Soundness / Broken symlinks check	6s
Soundness / Python lint check	9s
Soundness / Format check	-1s
Test / Swift SDK for Wasm Build (${{ matrix.swift_version }} - ${{ matrix.os_version }})	-1s
Soundness / Shell check	-1s
Soundness / API breakage check	0s
Soundness / Unacceptable language check	0s
	1h 24m 57s

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