Refactor: Replace unbounded thread spawning with rayon parallel itera… #1212

Job	Run time
Tests in Containers (ci-jupyter-container, ubuntu-latest, mcr.microsoft.com/devcontainers/univers...	4m 2s
Tests (ubuntu-latest, x86_64-unknown-linux-musl, yes)	8m 45s
Builds (macos-14, aarch64-apple-darwin, yes)	2m 36s
Tests (macos-latest, x86_64-apple-darwin, yes)	14m 17s
Builds (ubuntu-latest, x86_64-unknown-linux-musl, yes)	2m 5s
Tests in Containers (ci-homebrew-container, ubuntu-latest, homebrew/brew, x86_64-unknown-linux-musl)	3m 40s
Builds (windows-latest, aarch64-pc-windows-msvc)	3m 58s
Tests (windows-latest, x86_64-pc-windows-msvc, yes)	6m 59s
Env Tests (ci-poetry-custom, ubuntu-latest, x86_64-unknown-linux-musl)	2m 37s
Env Tests (ci-poetry-project, windows-latest, x86_64-pc-windows-msvc)	5m 7s
Builds (windows-latest, x86_64-pc-windows-msvc)	3m 52s
Env Tests (ci-poetry-global, windows-latest, x86_64-pc-windows-msvc)	6m 54s
Builds (macos-latest, x86_64-apple-darwin, yes)	3m 0s
Env Tests (ci-poetry-project, ubuntu-latest, x86_64-unknown-linux-musl)	2m 30s
Env Tests (ci-poetry-global, ubuntu-latest, x86_64-unknown-linux-musl)	2m 35s
Env Tests (ci-poetry-custom, windows-latest, x86_64-pc-windows-msvc)	5m 18s
Tests (macos-14, aarch64-apple-darwin, yes)	10m 39s
	1h 28m 54s

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