Check if a ledger device is correctly connected before running task

[Ethnical]

A problem we recently detected is that the simulation still runs even if the ledger is not detected (most of the time, this will fail because the transactions are not signed by the correct signers). See this example during tasks 021, 023, and 024 on Sepolia:

Expected Behavior:
The correct behavior would be to proceed with executing the task only if the wallet (Ledger) is detected.
If not, we should revert and display a clear message stating that the ledger is not unlocked or connected.