split `validate_dependencies_and_incompatibilities()`

https://github.com/KANAjetzt/godot-mod-loader/blob/6b411f846d6a9f8027a6ac7ed1f88941b5d4d493/addons/mod_loader/classes/mod_manifest.gd#L92-L94

```gdscript
	if (not validate_dependencies_and_incompatibilities(mod_id, dependencies, incompatibilities) or
		not validate_optional_dependencies(mod_id, optional_dependencies)):
		return
```