avoid checking rakudo-specific error in test
avoid checking rakudo-specific error in test

Remains fudged for Niecza but with different reason.

zostay/roast,laben/roast,skids/roast,cygx/roast,laben/roast,laben/roast,niner/roast,b2gills/roast,zostay/roast,b2gills/roast,zostay/roast,dankogai/roast,dogbert17/roast,b2gills/roast,niner/roast,niner/roast,skids/roast,bitrauser/roast,cygx/roast,skids/roast,perl6/roast,bitrauser/roast,cygx/roast,dogbert17/roast,dankogai/roast,dankogai/roast