I follow the procedure from this page:
https://fedoraproject.org/wiki/Getting_a_Fedora_package_in_EPEL
First, I was contact witch owner giflib package by the mail.
He wrote me that he is not interested in maintaining the package.
Second, I send message to this mailing list witch template 2.
Maybe this procedure need to be changed?
Now I'm not sure, but I think that I was installed libgdiplus package on my Centos 8
stream OS. I just can't find libgdiplus-devel package. I will check this in Monday.
All the best!