Recursivity for flatMap

[jmverges]

This needs recursivity https://github.com/kirschbaum-development/nova-inline-relationship/blob/b2ef5d02bc6502972692e2e6717598edf2ff88c6/src/Observers/NovaInlineRelationshipObserver.php#L98

a Panel could have inside a DependencyPanel or any other 3rd party stuff. Locally I just did

            ->flatMap(function ($value) {
                return Integrate::fields($value);
            })
            ->flatMap(function ($value) {
                return Integrate::fields($value);
            })

and I got it working