API endpoint /api/account/addresstokenbalance is returning ERC721s

🐛 Bug Report

Getting the token balance of ERC20s for an address returns a list that includes ERC721s.

📝 Description

The balanceService.getBalances(address) is returning a list of ERC20s along with ERC721s

🔄 Reproduction Steps

https://block-explorer-api.mainnet.zksync.io/api?module=account&action=addresstokenbalance&address=0x0f6bfc4C284e489B404715B3F2610b0eb50FdE35

as well as:

https://block-explorer-api.mainnet.zksync.io/address/0x0f6bfc4C284e489B404715B3F2610b0eb50FdE35

Checking the return data, the last item in the list is "empty" data for a token with a quantity of 1.

{
      // Contract address is for CyfrinFoundryCourseNft 
      "TokenAddress": "0xBbA202c6DA89646F13C11a63C4aF182E4fFd4c2e",
      "TokenName": "",
      "TokenSymbol": "",
      "TokenQuantity": "1",
      "TokenDivisor": ""
  }

🤔 Expected Behavior

Only ERC20s listed for an address.

😯 Current Behavior

ERC20 and ERC721 are listed

Start by tracing the /api/account/addresstokenbalance endpoint to balanceService.getBalances(address), then compare its returned items with the address page response. Reproduce the example request and verify that the result contains only ERC20 tokens, excluding the ERC721 entry with TokenQuantity "1" and empty metadata.