Fix(ZoneFile6.load): Add split statement to input read

[jlarsen-usgs]

fix failing CI (setup-micromamba@v2 issue on Windows)

[codecov]

Codecov Report

Attention: Patch coverage is 0% with 1 line in your changes missing coverage. Please review.

Project coverage is 76.0%. Comparing base (5555d15) to head (4624de8).
Report is 3 commits behind head on develop.

Files with missing lines	Patch %	Lines
flopy/utils/zonbud.py	0.0%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff            @@
##           develop   #2330     +/-   ##
=========================================
+ Coverage     74.3%   76.0%   +1.7%     
=========================================
  Files          294     294             
  Lines        59562   59531     -31     
=========================================
+ Hits         44282   45279    +997     
+ Misses       15280   14252   -1028     

Files with missing lines	Coverage Δ
flopy/utils/zonbud.py	67.0% <0.0%> (+0.1%)	⬆️

... and 145 files with indirect coverage changes