Contract class balances method calls are typed as implicit any

[MajorLift]

In the following, contract.balances and result are implicitly typed as any, because the Contract class doesn't have a balances method.

import { Contract } from '@ethersproject/contracts';
...
async getBalancesInSingleCall(
  ...
  ) {
    ...
    const contract = new Contract(
      contractAddress,
      abiSingleCallBalancesContract,
      provider,
    );
    const result = await contract.balances([selectedAddress], tokensToDetect);
    ...
  }
}

https://github.com/MetaMask/core/blob/main/packages/assets-controllers/src/AssetsContractController.ts#L522-L554

All tests for getBalancesInSingleCall only check for toBeDefined() or strictEquals({}), with the exception of the following:

• 'should track and use the currently selected chain ID and provider when getting balances in a single call'

The fact that this test passes at runtime suggests that either this bug is only an issue at the type level, or there is a fallback method being called instead.