Issue: Missing POST /eth/v1/beacon/pool/payload attestations endpoint required for Gloas spec

Issue: Missing POST /eth/v1/beacon/pool/payload attestations endpoint required for Gloas spec: a task in LegoFlow-SWE (Harbor dataset). Important: Solve this task using only the repository, files, documentation, tests, and tools available in the provided task environment. Do not use the internet…

The task

Important: Solve this task using only the repository, files, documentation, tests, and tools available in the provided task environment. Do not use the internet or any external search service to look up this issue, related pull requests, patches, commits, discussions, or ready-made solutions. Derive the solution…

Part of Lego-X/LegoFlow-SWE.