tesseract: kill caveats

These caveats assume imagemagick is installed, and we don't like caveats
that duplicate documentation.

Closes #19667.
Byobu 5.41

Closes #19695.

Signed-off-by: Jack Nagel <jacknagel@gmail.com>
python: distribute 0.6.38
python3: distribute 0.6.38
pypy 2.0
moreutils 0.48