Return empty array instead of an error

[tothszabi]

There are valid cases when a project does not contain any accessible schemes. One such case is if you generate a new Cocoapods project with a newer Cocoapods version. So it is fine to return an empty array instead of throwing an error.

Later in the code path we already had a validation to make sure we have a scheme with the given name:

go-xcode/xcodeproject/xcworkspace/schemes.go

Lines 82 to 98 in e6be8ef

	func (w Workspace) Scheme(name string) (*xcscheme.Scheme, string, error) {
	schemesByContainer, err := w.Schemes()
	if err != nil {
	return nil, "", err
	}
	normName := norm.NFC.String(name)
	for container, schemes := range schemesByContainer {
	for _, scheme := range schemes {
	if norm.NFC.String(scheme.Name) == normName {
	return &scheme, container, nil
	}
	}
	}
	return nil, "", xcscheme.NotFoundError{Scheme: name, Container: w.Name}
	}