use %__make %{?_smp_mflags} to run tests in %check
    
    We use %make_build and %make_install since 5038a3a (Use cgit.conf and
    config.mak for cgit/git build options, 2018-02-18).  The macros allow
    the make options to be overridden more easily.
    
    For the same reason, replace make with %__make when running the test
    suite.
    
    Add %{?_smp_mflags} from the %make_build macro.  In testing, this cuts
    the build time by as much as 30%.  In the case of the slowest koji arch
    (armv7hl), it was 9 minutes 31 seconds before and 6 minutes 33 seconds
    after.  It's a nice speedup.
    
    We don't use %make_build directly because it includes the -O option
    (%{_make_output_sync}) which doesn't play nicely with the test output
    during an interactive build or while tailing the build logs.
    
    We also don't include %{_make_verbose} from %make_build.  We set `V = 1`
    in cgit.conf (and config.mak for git), which is what %{_make_verbose}
    does.  The macro is not defined on EL < 9 either.