feat(v8): add command to sync V8 deps

[richardlau]

Add git node v8 deps to (re)sync V8 dependencies from V8's DEPS file.

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I started on this while exploring potentially adding Chromium's Rust crates (third_party/rust) to the Node.js source tree (although it looks like we might do our own vendoring to potentially allow other uses of Rust). It will also be useful for exploring adding third_party/libc++/src for V8's custom_libcxx to avoid requiring libatomic.

On its own it shouldn't do anything (other than revert any patches we have floated on top of the third_party deps). Its main use would be to test updates to lib/update-v8/constants.js or even V8's DEPS (if we ever want to roll forward a dependency (I expect that to be rare/unlikely)).

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 80.58%. Comparing base (d05ef11) to head (6f241c2).
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #1016   +/-   ##
=======================================
  Coverage   80.58%   80.58%           
=======================================
  Files          39       39           
  Lines        4754     4754           
=======================================
  Hits         3831     3831           
  Misses        923      923           

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