Break out _validate_energy_node() function as suggested #1920

Job	Run time
Shellcheck	4s
Prepare	47s
Dependency	3s
Ruff check and force	11s
Check commit	43s
Create pytest cache for Python 3.13	5s
Run pytest using Python 3.13	23s
Run mypy	7s
Process test coverage	10s
Build and publish Python 🐍 distributions 📦 to TestPyPI	20s
Process test complexity	6s
	2m 59s

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