Support arm cross compile

[bricerisingalgorand]

Summary

This PR is to take advantage of arm64's ability to run arm32 binaries. Using this, we are able to build for arm32 on arm64 hosts by running containers with arm32 OS's on them. This is much faster than our qemu set up because it doesn't rely on emulations. The binaries produced with this process work and the arm64/arm32 build times are as fast as the intel builds, reducing our build time by about an hour.

Test Plan

I ran our build pipeline against this branch using arm64 hosts and tested the produced artifacts using emulated cpu's to make sure they still work on their native architectures.

[tsachiherman]

did you test the resulting binaries on Raspberry PI ?

[bricerisingalgorand]

did you test the resulting binaries on Raspberry PI ?

I want to but I don't have an armv6 raspberry pi. Do you happen to have one handy?

[tsachiherman]

did you test the resulting binaries on Raspberry PI ?

I want to but I don't have an armv6 raspberry pi. Do you happen to have one handy?

I have one in the office - could you send me the produced binary and I'll give it a try tomorrow morning ?

[codecov-commenter]

Codecov Report

Merging #2923 (ba4e1ad) into master (b8b7281) will decrease coverage by 0.01%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master    #2923      +/-   ##
==========================================
- Coverage   47.33%   47.32%   -0.02%     
==========================================
  Files         351      351              
  Lines       56523    56523              
==========================================
- Hits        26754    26748       -6     
- Misses      26760    26766       +6     
  Partials     3009     3009              

Impacted Files	Coverage Δ
crypto/merkletrie/trie.go	66.42% <0.00%> (-2.19%)	⬇️
crypto/merkletrie/node.go	91.62% <0.00%> (-1.87%)	⬇️
network/requestTracker.go	70.25% <0.00%> (-0.87%)	⬇️
network/wsPeer.go	74.37% <0.00%> (-0.28%)	⬇️
ledger/acctupdates.go	62.46% <0.00%> (+0.33%)	⬆️

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[algojack]

Assuming test on raspberry pi goes well, lgtm

[tsachiherman]

I've tested this on raspberry pi 2, and it's working just fine.

[onetechnical]

Successfully tested on raspberry pi 4 as well.