chore: refactor pandas-like `narwhals_to_native_dtype` #5896

Job	Run time
pytest-38 (3.8, windows-latest)	1m 11s
pytest-38 (3.8, ubuntu-latest)	49s
pytest-full-coverage (3.11, ubuntu-latest)	3m 51s
pytest-windows (3.10, windows-latest)	10m 48s
pytest-full-coverage (3.13, ubuntu-latest)	3m 36s
pytest-windows (3.12, windows-latest)	4m 15s
	24m 30s

Provide feedback