fix(cvfdutil): fix skip_hanging_node_check

[oscarfasanchez]

vertexdict_keys was put out of the if condition skip_hanging_node_check, to avoid failure if the check is not necessary on some grids
Related to issue #2321

[wpbonelli]

Thanks @oscarfasanchez I moved the vertexdict_keys assignment above the conditional since it's needed both within it and below.

Not sure why the check might hang indefinitely in your use case. Can you send us the script to reproduce it? Presumably that while loop is never exited.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 76.3%. Comparing base (bb9824e) to head (17c7c98).
Report is 38 commits behind head on develop.

Additional details and impacted files

@@            Coverage Diff            @@
##           develop   #2423     +/-   ##
=========================================
+ Coverage     68.4%   76.3%   +7.8%     
=========================================
  Files          294     294             
  Lines        59390   59855    +465     
=========================================
+ Hits         40652   45690   +5038     
+ Misses       18738   14165   -4573     

Files with missing lines	Coverage Δ
flopy/utils/cvfdutil.py	82.5% <100.0%> (ø)

... and 247 files with indirect coverage changes