As this is marked as CC-BY 4.0 and they said "there is no need to credit me" I got curious if that actually works. As a layman section 8c of the license "No term or condition of this Public License will be waived and no failure to comply consented to unless expressly agreed to by the Licensor." seems like it might apply as them not insisting on credit might be considered consenting to not complying with the attribution requirements. However, based on my understanding anyone could adapt this, license their changes as CC0 and not credit the original creator, effectively turning this entire asset into a CC0 licensed one.

Can anyone with proper legal knowledge enlighten me or might this as well be dual licensed as CC0?