Move validation out of execute methods #3206

Job	Run time
Check for syntax errors	12s
Run model tests (3.8, windows-latest)	11m 33s
Run model tests (3.8, macos-latest)	6m 50s
Run model tests (3.9, windows-latest)	11m 41s
Run model tests (3.9, macos-latest)	8m 33s
Run model tests (3.10, windows-latest)	12m 7s
Run model tests (3.10, macos-latest)	9m 45s
Build sampledata archives	6m 9s
Run Workbench Tests (windows-latest)	11m 5s
Run Workbench Tests (macos-latest)	4m 8s
Build binaries (macos-latest)	36m 16s
Build binaries (windows-latest)	18m 38s
Check sdist (3.8, windows-latest)	9m 4s
Check sdist (3.8, macos-latest)	2m 20s
Check sdist (3.9, windows-latest)	5m 57s
Check sdist (3.9, macos-latest)	3m 18s
Check sdist (3.10, windows-latest)	6m 14s
Check sdist (3.10, macos-latest)	2m 46s
Validate Sampledata & User Guide	10m 27s
	2h 57m 3s

Provide feedback