metpy and PyInstaller are no longer compatible

[bwoodsend]

The problem is that two packages provide libtiff.5.dylib and those two copies are incompatible. I.e., after pip install metpy, this is what we get:

$ find . -name "libtiff*" -print
./lib/python3.9/site-packages/pyproj/.dylibs/libtiff.5.dylib
./lib/python3.9/site-packages/PIL/.dylibs/libtiff.5.dylib

And we actually do collect both, but due to path rewriting, the copy in _MEIPASS will be picked up (which in this case comes from PIL and is incompatible with pyproj):

('libtiff.5.dylib',
   '[...]/venv/lib/python3.9/site-packages/PIL/.dylibs/libtiff.5.dylib',
   'BINARY'),
[...]
('pyproj/.dylibs/libtiff.5.dylib',
   '[...]/venv/lib/python3.9/site-packages/pyproj/.dylibs/libtiff.5.dylib',
   'DATA'),

Originally posted in #374 (comment)