de-prioritize besu for trace requests

[pk910]

Summary

De-prioritize Besu clients for trace calls in the execution tx indexer.

Besu clients consume excessive resources when processing trace calls (debug_traceBlockByHash), often causing OOM crashes. This change modifies the client selection logic for trace operations to prefer non-Besu clients while still including Besu as a fallback.

Changes

• Modified getTraceClients() in indexer/execution/txindexer/loader.go to:
  • Separate clients into non-Besu and Besu lists
  • Prefer the primary client first (since it has the block data loaded), unless it's Besu
  • If the primary client is Besu, use it as the last option
  • Always include the primary client in the candidate list (reserved slot) since it's the only one guaranteed to have the block

Behavior

Primary Client	Order
Non-Besu	[primary, other-non-besu..., other-besu...]
Besu	[non-besu..., other-besu..., primary]