Don't assume axes parent is a figure (bug #44394) * axis.m: use "ancestor (ca, "figure")" in place of "get (ca, "parent")" * legend.m: use "ancestor (ca, "figure")" in place of "get (ca, "parent")" * colorbar.m: use "ancestor (ca, "figure")" in place of "get (ca, "parent")" * copyobj.m: use "ancestor (ca, "figure")" in place of "get (ca, "parent")" * hold.m: use "ancestor (ca, "figure")" in place of "get (ca, "parent")" * ishold.m: use "ancestor (ca, "figure")" in place of "get (ca, "parent")"