Set minimum state pivot to be at least the block after

[asdacap]

• Should fix chiado missing state issue when using fuzzer.
• This happens when the persisted state is equal to the sync pivot which on restart causes the start block to be equal to the persisted state block which is a problem as the block may not get downloaded in non validator mode. This can be seen with this log lone 2024-12-20 12:58:13.4925|INFO|Blockchain.BlockTree|16|Start block loaded from reorg boundary - 13411836 - where the persisted block is null.
• This set the state pivot to be at least sync pivot + 1.

Types of changes

What types of changes does your code introduce?

• Bugfix (a non-breaking change that fixes an issue)

Testing

Requires testing

• Yes
• No

If yes, did you write tests?

• Yes
• No