[5.0 -> main] refactor threading of snapshot_scheduler_test #4918

Job	Run time
Discover Versions	3s
Platform Cache / Discover Platforms	5s
Platform Cache / Build Platforms (none)	3s
Run Build Workflow / Build leap (reproducible)	8m 32s
Run Build Workflow / Build leap (ubuntu22)	8m 48s
Run Build Workflow / Build leap (ubuntu20)	9m 6s
Tests (ubuntu20)	3m 0s
Tests (ubuntu22)	3m 13s
Build deb packages (ubuntu20)	14m 31s
LR Tests (ubuntu20)	23m 54s
Tests (ubuntu20repro)	3m 1s
Build deb packages (ubuntu22)	16m 7s
NP Tests (ubuntu20)	7m 8s
LR Tests (ubuntu22)	23m 40s
Tests (ubuntu22repro)	3m 19s
Build deb packages (reproducible)	12m 1s
NP Tests (ubuntu22)	5m 35s
LR Tests (ubuntu20repro)	24m 2s
NP Tests (ubuntu20repro)	7m 7s
LR Tests (ubuntu22repro)	23m 48s
NP Tests (ubuntu22repro)	6m 18s
libtester tests (ubuntu20, build-tree)	8m 14s
libtester tests (ubuntu20, make-dev-install)	9m 48s
libtester tests (ubuntu20, deb-install)	4m 18s
libtester tests (ubuntu22, build-tree)	8m 44s
libtester tests (ubuntu22, make-dev-install)	9m 37s
libtester tests (ubuntu22, deb-install)	4m 36s
All Required Tests Passed	1s
	4h 8m 39s

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