Update Go-Get, take II

[theunrepentantgeek]

What this PR does / why we need it:

Often the go get step in our CI builds will fail.

This is due to delays in the default proxy used by the go CLI, specifically:

In order to improve our services' caching and serving latencies, new versions may not show up right away. If you want new code to be immediately available in the mirror, then first make sure there is a semantically versioned tag for this revision in the underlying source repository. Then explicitly request that version via go get module@version. The new version should be available within one minute.

Special notes for your reviewer:

Bypassing the proxy would invalidate the scenario we want to test, so I've juiced up the retries.

How does this PR make you feel:

[codecov-commenter]

Codecov Report

Merging #3380 (14bdbf8) into main (64714e3) will decrease coverage by 0.02%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##             main    #3380      +/-   ##
==========================================
- Coverage   54.51%   54.49%   -0.02%     
==========================================
  Files        1515     1515              
  Lines      636546   636546              
==========================================
- Hits       346982   346895      -87     
- Misses     232908   232989      +81     
- Partials    56656    56662       +6     

see 32 files with indirect coverage changes

[matthchr]

We should monitor how long this takes, because if it actually is taking anywhere near 5m we should probably just strip this bit out into its own async check rather than putting it here. Adding +5m to the CI run would ideally be avoided.