release(1.2.7) update MODFLOW 6 version to 6.4.1

[jdhughes-usgs]

Update download._request_get() and dowload._request_header() to improve ability to retry url requests. Improved flakyness of autotest/test_requests.py.

[codecov[bot]]

Codecov Report

Merging #128 (a6d9aa8) into master (8ef06bb) will increase coverage by 0.554%. The diff coverage is 88.524%.

@@              Coverage Diff              @@
##            master      #128       +/-   ##
=============================================
+ Coverage   61.233%   61.787%   +0.554%     
=============================================
  Files           21        21               
  Lines         4589      4598        +9     
=============================================
+ Hits          2810      2841       +31     
+ Misses        1779      1757       -22     

Impacted Files	Coverage Δ
pymake/cmds/createjson.py	0.000% <ø> (ø)
pymake/utils/usgsprograms.py	85.167% <84.848%> (+1.265%)	:arrow_up:
pymake/utils/download.py	72.191% <92.857%> (+4.954%)	:arrow_up:
pymake/pymake_base.py	86.794% <0.000%> (+0.128%)	:arrow_up:
pymake/utils/_compiler_switches.py	76.200% <0.000%> (+0.218%)	:arrow_up:
pymake/utils/_meson_build.py	28.333% <0.000%> (+0.833%)	:arrow_up: