Bad messaging around updating firmware

## What Happened
I was attempting to update my system firmware since I noticed that it needed an update. I clicked update, and it started trying to update.
My laptop was not actually plugged in, so this message seems out of place. There's no way I could unplug the device.

Then, the update failed because my device wasn't plugged in.
There was no way to anticipate that my device needed to be plugged in to perform this update. I think that either it should not be possible to perform the update at all if the device is not plugged in, or there should be a manual override in the GUI that exposes this "forced' option that the error message mentions.

## Expected Behavior

Based on the information I was given in the GUI, I expected the update to work. The only way to discover that your laptop needs to be plugged in for a firmware update is to attempt an update and have it fail.

## Steps to Reproduce

1. Unplug laptop
2. Attempt to update firmware

### Logs

## Platform Information

I'm running elementary OS 6 beta. Here's the version I have installed from `apt`: `switchboard-plug-about/focal,now 2.6.3+r1267+pkg812~daily~ubuntu6.1`