ref: replace git clone with zip downloads, reuse retry machinery

[joshuarli]

instead of getsentry/sentry#114194 we can just completely drop git in favor of downloading source archives at the cost of a few MB (snuba, relay) vs sparsely checking out devservices/

it's worth it for peace of mind and is overall much simpler (look at all the removed code!)

no config changes required; we can construct a github archive zip url from existing configuration

i also took the liberty to deduplicate a retry wrapper since it's now used in 3 places

also i tested this manually with fresh colima and it works

[hubertdeng123]

I'm not convinced this is a better approach since the zip file is downloaded on every devservices call. Sparse checkout allowed us to return early if there weren't any changes. Can you explain more on the benefits here?

I know that git clone was creating issues in CI because of a silent runner upgrade from GitHub, but also I know that we use git clone in a lot of areas so trying to understand more here.

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