refactor: payload envelope input -- pruneBelowParent

[jeffoodchain]

Motivation
According to #9318

Description

Change from iterating all the ancestor to only cache in seenPayloadEnvelopeInput/pruneBelowParent

Closes #9318

AI Assistance Disclosure

collaborate with claude code

[gemini-code-assist]

Code Review

This pull request refactors the pruneBelowParent logic in SeenPayloadEnvelopeInput to use forkChoice.isDescendant for more precise pruning of ancestor blocks, ensuring that entries on other forks are preserved. Unit tests have been updated to reflect this change and include a new test case for fork handling. Feedback suggests using PayloadStatus.PENDING instead of PayloadStatus.FULL to improve robustness in identifying ancestors, particularly for the Gloas fork, and notes a typo in the source code comments.

[gemini-code-assist]

The check for ancestor status should use PayloadStatus.PENDING instead of PayloadStatus.FULL. In the Gloas fork, every block root has a PENDING variant, but the FULL variant is only created once the execution payload is available. If a block in the cache is an ancestor but hasn't transitioned to FULL status in fork choice (e.g., if it was processed optimistically or if the node switched to a fork that doesn't require its payload), using PayloadStatus.FULL will cause isDescendant to return false, preventing the entry from being pruned until finalization. Using PayloadStatus.PENDING is more robust as it correctly identifies the block as an ancestor regardless of its payload status.

Also, there is a typo in the comment: "cariant" should be "variant".

        // Check if the cached block is an ancestor of the current parent block.
        // Using PENDING status for the ancestor is more robust as every Gloas block
        // has a PENDING variant, while the FULL variant may not exist yet or at all.
        this.forkChoice.isDescendant(
          input.blockRootHex,
          PayloadStatus.PENDING,
          parentBlock.blockRoot,
          parentBlock.payloadStatus
        )