fix(rpcs): remove dead and defunct RPC endpoints for BSC (56)

[Lukecele]

Description

This PR cleans up dead and defunct public RPC endpoints for BNB Smart Chain (ChainID: 56) in constants/extraRpcs.js that currently fail network resolution or return HTTP/auth errors:

• https://bsc.campioneinfrastructure.com: DNS resolution failure (NXDOMAIN)
• https://bsc-dataseed6.dict.life/: DNS resolution failure (NXDOMAIN)
• https://bsc.rpcgator.com/: DNS resolution failure (NXDOMAIN)
• https://nodes.vefinetwork.org/smartchain: DNS resolution failure (NXDOMAIN)
• https://public.stackup.sh/api/v1/node/bsc-mainnet: Service discontinued / dead host
• https://bsc.therpc.io: DNS resolution failure (NXDOMAIN)
• https://rpc.poolz.finance/bsc: DNS resolution failure (NXDOMAIN)
• https://gw-aql.tomo.services/v1/bnbchain/aql_live_... (https + wss): Service discontinued (timeout / failed)
• https://bsc-rpc.keccak.io: Requires authenticated paid account (not a public free endpoint)
• https://bsc-rpc-public.chainpulse.cc/: Server down (Cloudflare 521)
• https://bsc-mainnet.rpcfast.com?api_key=...: Expired API key returning error -32000

Verification

• Ran node tests/check-duplicate-keys.js — All duplicate key and syntax checks passed:

  ✓ extraRpcs.js has valid JavaScript syntax
  ✓ chainIds.js has valid JavaScript syntax
  ✓ No duplicate keys found in privacyStatement (checked 144 keys)
  ✓ No duplicate chainId keys found in extraRpcs (checked 1025 keys)
  ✓ All duplicate key checks passed!
  

• Verified that all remaining active RPC fallbacks for BSC (56) are healthy and returning valid responses.