Fix #72482: Ilegal write/read access caused by gdImageAALine overflow

Fix #72482: Ilegal write/read access caused by gdImageAALine overflow

Instead of rolling our own bounds check we use clip_1d() as it's done
in gdImageLine() and in external libgd. We must not pass the image
width and height, respectively, but rather the largest ordinate value
that is allowed to be accessed, i.e. width-1 and height-1,
respectively.