When processing a transaction with London fork rules, EIP-1559 mandates
checking that the sender must have sufficient balance to cover gas * gasFeeCap.

In the EIP's pseudocode, this check happens after the value transferred by the
transaction has already been deducted. However, in go-ethereum, the balance
has not yet been updated when the check happens, and therefore needs to be
added explicitly.
Co-authored-by: Martin Holst Swende <martin@swende.se>