Fix: End logger after ensuring flushing file transport is done #25737

[manuelkue]

I've seen that the logger is not ended anymore after #25737
If that behavior is fine this PR can be closed, otherwise I'd like to contribute a fix :)

By moving the this.logger.end() after the await, it is ensured that the Promise resolves before ending the logger.
This way the fileTransport's finish event has to happen before the end() is executed.
If there's no active fileTransport the logger can be ended immediately.

[Koenkk]

This has been done on purpose, otherwise Z2M crashes with Error: write after end when something is logged after the logger is ended (this happens when zigbee-herdsman stop unexpectedly)

[manuelkue]

Yes, I had guessed that this error appeared because the logger was previously closed but the fileTransport was not finished yet. So during or at the end of the fileTransport some log would be written, but the logger has been closed already.

My PR solves this issue by moving the this.logger.end() after the finished fileTransport / after its await.
My thought was that the error appeared before #25737, because the ending happened at the start and not at the end of public async end() when the Promise is finally resolved :)

So if you think that the logger should be closed indeed at some time I'd think this fix would do it.
If the logger doesn't have to be ended at all it's probably fine to just let it be as it is and close this PR.

[Koenkk]

Can you check if this works now?

async exit(code: number, restart = false): Promise<void> {
    console.log('Call logger.end()');
    await logger.end();
    console.log('Before log after end');
    logger.info('LOG AFTER END');
    console.log('After log after end');
    return await this.exitCallback(code, restart);
}

(from #25737)