fix: sea error handling

[nikwen]

throw new Error(error) does not terminate the SEA process when used via Forge's MakerSquirrel.

I had a case where due to a misconfiguration an error was thrown in the try block and subsequently caught in the catch block that this PR modifies. The process didn't exit upon reaching throw new Error(error). Instead, it kept running indefinitely. (This reproduced reliably every time I ran it.)

As a result, my electron-forge make command kept running indefinitely (without succeeding or failing) because squirrel.exe --releasify thought signing (via the SEA) was still ongoing.

My guess is that it has something to do with stdout/stderr. If I log the error in the catch block using console.log or console.error, the process also does not terminate.

The issue was hard to debug. It took me ~4 hours to figure out. Hope this will save someone else from having to do the same.