rpmautospec koji plugin bakes in the result of %autorelease and
%autochangelog into the SRPM. When used on a Fedora or EL 9 machine with
rpmautospec installed, fedpkg does the same. However, it's currently
impossible to rebuild specfiles that use rpmautospec on EL 8 itself due
to the unexpanded %autorelease and %autochangelog macros failing the
SRPM build.
This adds the same fallback %autorelease and %autochangelog macro
definitions that are available in the Fedora and EPEL 9 buildroots. This
allows locally rebuilding packages that use rpmautospec with plain
rpmbuild or fedpkg on an EL 8 system or with `mock --spec`.