race condition git push when run more than one commands in parallel

[mordamax]

Reported by @acatangiu
paritytech/polkadot-sdk#2619 (comment)

When running benchmarks 1,2,3
it pushes 1, but 2,3 remain to be not up to date, so it fails pushing the diff

Proposed fix:
run git pull --rebase before pushing and re-try if that still fails, as there's still chance