devel/allegro: Fix build with CMake >= 3.31.0

For some reason, the check for XDGAQueryExtension in Xxf86dga was
failing in previous versions of CMake, but it now succeeds, which is the
expected result. It's an oversimplified check, however, that just adds
the library name without path if found.

Just using raw data from pkg_check_modules() results in a similar
problem, which this project does. The ALSA option already had the
usual workaround for this scenario (USES+=localbase:ldflags) in place,
but the JACK option did not. Build would fail if the JACK option was
enabled, but not ALSA even in previous versions of CMake.

This version of allegro is ancient, so just elevate the workaround
to the port level.

PR: 282725