Port GerryChain adjacency calcs to Shapely 2.0

[InnovativeInventor]

Shapely 2.0 will introduce breaking changes for GerryChain. In particular, our adjacency calculation code will break (and we won't be able to make new dual graphs). Although Shapely 2.0 hasn't stabilized yet, it appears that recent updates in our dependencies (i.e. geopandas) has caused some issues to show up prior to Shapely 2.0 being offically stable.

Relevant issues:

• Fixes Shapely deprecation warning #392
• Closes Use maup for adjacencies? #287

#369 was originally a stop-gap fix for this PR. We should be able to remove the import warning in gerrychain/__init__.py.

[InnovativeInventor]

Note: tests are failing due to Shapely 2.0 not being stable yet. Do not merge this PR. We should also add some dependency constraints to ensure that if GerryChain gets updated in a user's install, Shapely will get upgraded as well.

To be clear: this is a breaking change. This PR aims to deprecate Shapely < 2.0.

[InnovativeInventor]

We should port maup to use GerryChain's adjacency calculations (or vice-versa) so maup does not suffer from the same impending deprecation issue.

[codecov]

Codecov Report

Merging #405 (7453d80) into main (3179ac1) will decrease coverage by 0.11%.
The diff coverage is 75.00%.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #405      +/-   ##
==========================================
- Coverage   89.10%   89.00%   -0.11%     
==========================================
  Files          39       39              
  Lines        1772     1774       +2     
==========================================
  Hits         1579     1579              
- Misses        193      195       +2     

Impacted Files	Coverage Δ
gerrychain/graph/graph.py	91.12% <66.66%> (-1.00%)	⬇️
gerrychain/graph/adjacency.py	88.88% <100.00%> (-0.59%)	⬇️

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