devenv: move legacy setup-git to sync

[joshuarli]

First step towards cleaning up all the legacy stuff. This moves setup-git to sync. context: https://github.com/getsentry/getsentry/pull/13540/files#diff-76ed074a9305c04054cdebb9e9aad2d818052b07091de1f20cad0bbac34ffb52R28

Also removes the old make bootstrap and make develop now just runs devenv sync.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 78.14%. Comparing base (f4df6e0) to head (0058bf9).
Report is 110 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master   #72870      +/-   ##
==========================================
+ Coverage   78.10%   78.14%   +0.03%     
==========================================
  Files        6660     6656       -4     
  Lines      297707   297219     -488     
  Branches    51226    51127      -99     
==========================================
- Hits       232533   232265     -268     
+ Misses      58904    58701     -203     
+ Partials     6270     6253      -17     

see 101 files with indirect coverage changes

[github-actions]

🚨 Warning: This pull request contains Frontend and Backend changes!

It's discouraged to make changes to Sentry's Frontend and Backend in a single pull request. The Frontend and Backend are not atomically deployed. If the changes are interdependent of each other, they must be separated into two pull requests and be made forward or backwards compatible, such that the Backend or Frontend can be safely deployed independently.

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