Allow running full glados suite without PANDA_OPS infra

[kdeme]

I think there are currently two issues that make it mandatory (or partial mandatory) for using PANDA_OPS:

• docker compose requires currently PANDA_OPS related ENV to be set, fixed here: Remove mandatory PANDAOPS ENV from docker-compose #356
• Beacon glados monitor: Has hardcoded PANDA_OPS consensus node set:

  glados/glados-monitor/src/beacon.rs

  Line 21 in 3a7a3df

  pub const PANDA_OPS_BEACON: &str = "https://nimbus.mainnet.ethpandaops.io";

  . And uses this call:

  glados/glados-monitor/src/beacon.rs

  Line 201 in 3a7a3df

  pub fn panda_ops_http() -> anyhow::Result<HttpClient> {

I think that can be resolved by making those headers optional like is done here for the web3 version:

glados/glados-monitor/src/lib.rs

Line 275 in 3a7a3df

if provider_url.contains("ethpandaops.io") {