Is the Red Hammer 1.85 Compatibility patch included in the GOTY edition's installation?

Yes, it is. Game Of The Year edition users do not need to download and install the Red Hammer 1.85 Compatibility patch. Furthermore, if you upgrade to OFP GOTY version 1.90 and above, you do not need to and you should not attempt to install the Red Hammer 1.90 Compatibility patch. You can read more about that here.