SIMULATE_WITHOUT_LEDGER should check the value to 1

[Ethnical]

For now the SIMULATE_WITHOUT_LEDGER is used to simulate without the ledger and this is very useful.
However, a "bug" can occurs when tasks writer wants to make this as more interactive.

So we would like to have the

• SIMULATE_WITHOUT_LEDGER = 0 is disabled.
• SIMULATE_WITHOUT_LEDGER = 1 is enabled.

For now, only if the SIMULATE_WITHOUT_LEDGER is set this will enable this and not check if the value is 0 or 1.

[sebastianst]

I suggest we change the semantics to true and false so that it's the same as foundry forge script parsing of bool env vars.