ci: Remove go-mod-download

[mslipper]

No description provided.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 43.93%. Comparing base (53b3af7) to head (c12d82a).
Report is 8 commits behind head on develop.

Additional details and impacted files

@@             Coverage Diff             @@
##           develop   #13277      +/-   ##
===========================================
- Coverage    46.95%   43.93%   -3.02%     
===========================================
  Files          923      810     -113     
  Lines        77648    72553    -5095     
  Branches       849        0     -849     
===========================================
- Hits         36456    31875    -4581     
+ Misses       38584    38126     -458     
+ Partials      2608     2552      -56     

Flag	Coverage Δ
cannon-go-tests-32	61.85% <ø> (-2.02%)	⬇️
cannon-go-tests-64	56.72% <ø> (-1.66%)	⬇️
contracts-bedrock-tests	?

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see 127 files with indirect coverage changes

[geoknee]

Can you add some context about this change? Does it reduce running time on CI?

[mslipper]

This job was used to warm CircleCI's build cache. Now that we use a custom build box, there's no need to do this anymore since the task runners on the box share a local Go build cache.