Upgrade intx to 0.12.1 and ethash to 1.1.0

[chfast]

No description provided.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 94.50%. Comparing base (df85089) to head (4e9cfc7).
Report is 1 commits behind head on master.

Additional details and impacted files

@@           Coverage Diff           @@
##           master    #1131   +/-   ##
=======================================
  Coverage   94.50%   94.50%           
=======================================
  Files         167      167           
  Lines       18198    18198           
=======================================
  Hits        17198    17198           
  Misses       1000     1000           

Flag	Coverage Δ
eof_execution_spec_tests	15.34% <ø> (ø)
ethereum_tests	28.32% <ø> (ø)
ethereum_tests_silkpre	20.83% <ø> (ø)
execution_spec_tests	21.10% <ø> (ø)
unittests	89.76% <ø> (ø)

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