update mf6 version

[jdhughes-usgs]

No description provided.

[codecov]

Codecov Report

Attention: 2 lines in your changes are missing coverage. Please review.

Comparison is base (7d05f3e) 81.469% compared to head (48b0589) 82.527%.

Additional details and impacted files

@@              Coverage Diff              @@
##            master      #154       +/-   ##
=============================================
+ Coverage   81.469%   82.527%   +1.057%     
=============================================
  Files           20        20               
  Lines         3470      3474        +4     
=============================================
+ Hits          2827      2867       +40     
+ Misses         643       607       -36     

Files	Coverage Δ
pymake/config.py	100.000% <100.000%> (ø)
pymake/pymake.py	78.395% <ø> (ø)
pymake/utils/_usgs_src_update.py	94.587% <ø> (+4.381%)	⬆️
pymake/pymake_base.py	90.944% <77.777%> (-0.213%)	⬇️

... and 1 file with indirect coverage changes