[KGA-82] [KGA-80] fix: codehash commitment

[enitrat]

Fixes the codehash assigned to an account upon deployment as per code-423n4/2024-09-kakarot-findings#10

• In any case, the codehash of an account is keccak(code_bytes)
• IF that account has no code, nonce nor balance, then extcodehash opcode returns 0.

As such, upon deploying the starknet contract corresponding to an account, we should always set the codehash to self.code_hash

---

This change is 

[codecov]

Codecov Report

Attention: Patch coverage is 0% with 1 line in your changes missing coverage. Please review.

Project coverage is 63.4%. Comparing base (5c96bb7) to head (cdaddf4).
Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
cairo_zero/backend/starknet.cairo	0.0%	1 Missing ⚠️

Additional details and impacted files

@@          Coverage Diff          @@
##            main   #1566   +/-   ##
=====================================
  Coverage   63.4%   63.4%           
=====================================
  Files         44      44           
  Lines       8349    8350    +1     
=====================================
+ Hits        5298    5300    +2     
+ Misses      3051    3050    -1     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[ClementWalter]

remove the set_code_hash call in if (self.created != FALSE) { then

[notion-workspace]

Incorrect state for accounts without code and nonce

[notion-workspace]

Three valid signatures for the same message

[enitrat]

remove the set_code_hash call in if (self.created != FALSE) { then

I think you should always set the codehash when writing the bytecode. Perhaps there are instances where the starknet contract is already deployed and the code is re-written: re-deployed selfdestructed contracts.