ci: extract go artifacts upload code into a script

[ptrus]

Extracted from #3124 since otherwise the next longtest run will fail.

[codecov]

Codecov Report

Merging #3125 into master will increase coverage by 0.04%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master    #3125      +/-   ##
==========================================
+ Coverage   68.39%   68.44%   +0.04%     
==========================================
  Files         376      376              
  Lines       37066    37066              
==========================================
+ Hits        25353    25370      +17     
+ Misses       8481     8455      -26     
- Partials     3232     3241       +9     

Impacted Files	Coverage Δ
go/consensus/tendermint/api/errors.go	86.66% <0.00%> (-13.34%)	⬇️
go/runtime/host/sandbox/sandbox.go	67.28% <0.00%> (-9.30%)	⬇️
go/common/grpc/policy/policy.go	64.38% <0.00%> (-6.85%)	⬇️
...n/crypto/signature/signers/memory/memory_signer.go	71.42% <0.00%> (-4.77%)	⬇️
go/worker/common/committee/runtime_host.go	65.71% <0.00%> (-4.77%)	⬇️
go/consensus/tendermint/apps/staking/state/gas.go	77.58% <0.00%> (-3.45%)	⬇️
go/storage/metrics.go	84.78% <0.00%> (-3.27%)	⬇️
go/storage/api/root_cache.go	72.41% <0.00%> (-2.30%)	⬇️
go/storage/database/database.go	72.26% <0.00%> (-1.69%)	⬇️
go/staking/api/grpc.go	54.56% <0.00%> (-0.81%)	⬇️
... and 18 more

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