go/runtime/host/sandbox: Retry Call in case the runtime is not yet ready

[kostko]

Issue discovered in long-term tests.

[codecov]

Codecov Report

Merging #2967 into master will decrease coverage by 0.18%.
The diff coverage is 85.71%.

@@            Coverage Diff             @@
##           master    #2967      +/-   ##
==========================================
- Coverage   68.62%   68.44%   -0.19%     
==========================================
  Files         360      360              
  Lines       35278    35273       -5     
==========================================
- Hits        24211    24144      -67     
- Misses       7971     8035      +64     
+ Partials     3096     3094       -2     

Impacted Files	Coverage Δ
go/runtime/host/sandbox/sandbox.go	75.74% <84.61%> (-0.21%)	⬇️
go/worker/common/committee/runtime_host.go	65.71% <100.00%> (-3.26%)	⬇️
go/worker/compute/executor/committee/state.go	74.07% <0.00%> (-11.12%)	⬇️
go/worker/compute/executor/committee/node.go	61.03% <0.00%> (-6.53%)	⬇️
.../consensus/tendermint/apps/epochtime_mock/state.go	82.97% <0.00%> (-4.26%)	⬇️
go/storage/mkvs/lookup.go	75.51% <0.00%> (-4.09%)	⬇️
go/worker/compute/txnscheduler/committee/node.go	61.26% <0.00%> (-3.91%)	⬇️
go/runtime/host/protocol/connection.go	61.53% <0.00%> (-3.85%)	⬇️
go/consensus/tendermint/apps/staking/state/gas.go	79.62% <0.00%> (-3.71%)	⬇️
go/storage/metrics.go	88.04% <0.00%> (-3.27%)	⬇️
... and 24 more

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