simplify by default in `*_tessellation()`

[jGaboardi]

@martinfleis -- I am working on re-upping spec000, which would bring shapely==v2.1 up to the oldest version.

I am seeing these notes in morphological_tessellation() and enclosed_tessellation().

# TODO: remove the keyword and do simplification by default once it is
# safe to pin shapely 2.1

So we want to do this, correct?:

1. Give a deprecation warning that the simplify removed in a later release and hardcode simplify=True within both the functions
2. Remove the key word entirely, maybe after the next release

[martinfleis]

I would hardcode simplify=True but temporarily keep the keyword around with no effect (simplify=None). If a user specifies bool, we show a warning that it has no effect and that the keyword itself will be removed.