feat(anvil): Support mining blocks with same timestamp as previous block

[domob1812]

Component

Anvil

Describe the feature you would like

As far as I am aware, EVM chains can support that a block has the same timestamp as a previous block, as that is required to support sub-second block times. It seems that anvil does not allow me to mine a block with the same timestamp as the previous block's (with evm_mine), as it then complains with:

Timestamp error: 1600000100 is lower than or equal to previous block's timestamp

I think it would be helpful to support this, so that we can actually test smart contracts handle a situation like this correctly (in case there is subtle time-dependent logic contained in them).

Additional context

No response

[grandizzy]

@domob1812 I think this scenario should be solved with #7931 and set --block-time to 0

[yash-atreya]

@domob1812 This is now supported

[Rubilmax]

I'm not sure it is related to this issue, but with the latest version of anvil, with auto mining, there are now some transactions that are mined in a new block with the same timestamp as the previous one (without tweaking anything in anvil)

EDIT: if I call setBlockTimestampInterval with interval 1 then it reverts to the expected behavior of block timestamp interval of 1s

[grandizzy]

@Rubilmax mind to open a ticket with a way to reproduce the problem you see? thank you!