v8: use primordials in startup_snapshot.js

[Ayoub-Mabrouk]

Replace native array methods (.push, .shift) with primordials (ArrayPrototypePush, ArrayPrototypeShift) in lib/internal/v8/startup_snapshot.js for consistency and security.

This improves protection against prototype pollution and aligns with the primordials pattern used throughout the codebase.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 88.54%. Comparing base (05d6b9b) to head (63cd1b4).
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main   #61199   +/-   ##
=======================================
  Coverage   88.53%   88.54%           
=======================================
  Files         703      703           
  Lines      208599   208604    +5     
  Branches    40229    40229           
=======================================
+ Hits       184685   184698   +13     
+ Misses      15939    15912   -27     
- Partials     7975     7994   +19     

Files with missing lines	Coverage Δ
lib/internal/v8/startup_snapshot.js	95.55% <100.00%> (+0.17%)	⬆️

... and 33 files with indirect coverage changes

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[avivkeller]

Please amend your commit to abide by the guidelines