Updated mock-core-configs v36.4 deployed to Fedora Copr

Hello maintainers, just heads-up (on breakage today, I hope). To bring several config fixes (especially for the broken centos-stream chroots), the mock-core-configs was updated today. This though also gave us an opportunity to add EPEL 9 configs. Feel free to experiment with them. Note though Enterprise Linux 9 is not yet available - so the EPEL 9 chroots are currently built against CentOS Stream 9 + EPEL 9 (similarly to what is done officially in Koji ATM). This update also means that 'epel-8' configs disappeared from the package [1]. To avoid build failures - for now - we provide a compat symlink from 'epel-8' config to 'centos+epel-8' in Copr. This basically means EPEL 8 configs haven't been changed at all, for now. Some time early in 2022 we will try to re-configure EPEL 8 chroots against RHEL 8 (subscribed content) + EPEL 8. That's because CentOS 8 goes EOL, [2]. [1] Mock release notes: https://rpm-software-management.github.io/mock/Release-Notes-2.16 [2] RHEL+EPEL Fedora devel discussion: https://lists.fedoraproject.org/archives/list/devel@lists.fedoraproject.o... Pavel