feat: onhost supervisor remove condvar approach #1019

Job	Run time
codespell	12s
cargo clippy	2m 5s
cargo shear (unused dependencies)	14s
Build release binaries	2m 37s
tests as root	3m 56s
cargo doc	1m 43s
Unit, docs and onhost integration tests	6m 54s
cargo fmt	13s
⚖️ Check third party licenses	4m 49s
ubuntu / stable / coverage	3m 57s
Unit test for embedded downloader	30s
K8s integration tests (flux-self-update)	6m 58s
K8s integration tests (part1)	8m 58s
build-windows-binary	4m 16s
K8s integration tests (part2)	6m 15s
security / Rust audit scanner	2m 43s
k8s-e2e-tests / K8s e2e tests infra	9m 33s
k8s-e2e-tests / K8s e2e tests	2s
🟢 All required checks and tests pass	3s
	1h 5m 58s

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