Drop or disable `kvsetkeys` patches

[muzimuzhi]

from https://github.com/muzimuzhi/thmtools/issues/34#issuecomment-1435914915

(Off the top of my head hence might be inaccurate and even totally wrong.)

• Drop patches for very old version of kvsetkeys.
• Disable remaining patches to kvsetkeys by default and perhaps provide a new package option to enable them.