Hello,
could you please add repositories from https://copr.fedorainfracloud.org/coprs/dmalcolm/gcc-latest/ to the corresponding mock configs used by https://openscanhub.fedoraproject.org/?
It should be safe to add them to the default configuration because the gcc-latest package will not be installed unless a user explicitly requests it (or the scanned SRPM depends on it, which is unlikely).
There is a draft pull request to make csmock-plugin-gcc optionally consume the SARIF output of GCC and it depends on this COPR: https://github.com/csutils/csmock/pull/187
Kamil