fix: handle EIP-4844 transactions in underpriced check

[fishingpi]

Problem

Previously, the is_underpriced function within the mempool-rebroadcaster crate did not explicitly account for EIP-4844 (Blob) transactions. As a result, any EIP-4844 transactions encountered were incorrectly categorized by the default _ match arm as "unknown transaction type" and subsequently treated as underpriced. This led to these transactions being filtered out from the mempool, preventing their proper rebroadcasting.

Solution

This Pull Request addresses the issue by updating the is_underpriced function in rebroadcaster.rs to correctly identify and process EIP-4844 transactions. The changes include:
Importing EIP4844_TX_TYPE_ID: The alloy_eips::eip2718 module now explicitly imports EIP4844_TX_TYPE_ID.
Updating is_underpriced logic: The EIP1559_TX_TYPE_ID match arm has been extended to include EIP4844_TX_TYPE_ID. This ensures that EIP-4844 transactions are evaluated based on their max_fee_per_gas against the base_fee, aligning their handling with other EIP-1559-like transactions.

Impact

This fix ensures that EIP-4844 transactions are no longer erroneously filtered out due to incorrect pricing assessment. By properly handling these transaction types, the mempool-rebroadcaster will maintain a more accurate representation of the mempool contents and facilitate the correct rebroadcasting of all supported transaction types, including Blob transactions.

Testing

Existing unit and end-to-end tests for the mempool-rebroadcaster crate were executed and passed successfully after applying this fix, confirming that the changes do not introduce regressions and the intended behavior for EIP-4844 transactions is now correctly implemented.
Branch: fix/handle-eip4844-txns

[cb-heimdall]

🟡 Heimdall Review Status

Requirement	Status	More Info
Reviews	🟡 0/1	Denominator calculation Show calculation 1 if user is bot 0 1 if user is external 0 2 if repo is sensitive 0 From .codeflow.yml 1 Additional review requirements Show calculation Max 0 0 From CODEOWNERS 0 Global minimum 0 Max 1 1 1 if commit is unverified 1 Sum 2

[danyalprout]

Thanks for the PR, we don't currently support EIP-4844 transactions, so this case should never happen (we're also going to delete this code soon).