ef844badd6
Selection mask is included in the stroke interpolation tool in
297b97f2df, however sometimes there will
be mismatches for when start/end curve count isn't the same. This fix
ensures that the interpolation operator only works on the max amount of
curves that can fit in both start and end side of the interpolation.
Pull Request: https://projects.blender.org/blender/blender/pulls/134484