refactor: Skip "usual" gas estimation when proposing blocks

[LHerskind]

When we are proposing a block, we will sometimes be doing so BEFORE we are actually within out designated slot. We will be doing so as the transaction can at the earliest be included in the next ethereum block, so we might be doing a simulation of "the future". When doing so in viem though, it will be using the current timestamp so reaching the time check will cause a failure.