meson: Use separate lists for non-ivf test files

Also fix some other minor issues.

10-bit/argon/meson.build

@@ -22,7 +22,7 @@
 # (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 # SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
-tests += [
+tests_obu += [
 	['test185_302', files('test185_302.obu'), 'c7e94ed7170edbb3a05f231bac699dbd'],
 ]