Reduce complexity of legacy -helper _all_appliances() #5639

Job	Run time
Shellcheck	5s
Dependency	4s
Cache identify	8s
Prepare	25s
Ruff check and force	18s
Check commit	40s
Run pytest using Python 3.13	26s
Run mypy	20s
Process test coverage	18s
Build and publish Python 🐍 distributions 📦 to TestPyPI	29s
Process test complexity	14s
	3m 27s

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