fix(protocol): fix parent metahash check for the first block

[dantaik]

The check didn't work for block 1 as the genesis block's metahash is 0.

Inspired by code-423n4/2024-03-taiko-findings#218

[openzeppelin-code]

fix(protocol): fix parent metahash check for the first block

Generated at commit: 3229f8092aac5f699abf2fb593c269c8f7af82ce

🚨 Report Summary

	Severity Level	Results
Contracts	Critical High Medium Low Note Total	2 2 0 3 39 46
Dependencies	Critical High Medium Low Note Total	0 0 0 0 0 0

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