The current script based on fontforge seems to have a few problems.
The generated fonts show glitches, for example in Cyberpunk 2077 for
Thai and in FIFA 22 for Arabic.
I don't precisely know what is the problem, and it might be that
the real bug is in the rendering code rather than in the merging
script. But since this seems to work better overall, I'm sticking
with it.
CW-Bug-Id: #20302
