fix: Remove confusing Notification regarding System updates

[remggo]

This commit removes the "System passed checks, updating ..." which is confusing as it will trigger every 6 hours even if there is no update available to install.

If there are other opinions on how to solve this, please let me know and I am happy to code something up.
I was just very confused the last days that my system "seemed" to update, but there were no system updates available.
Maybe there could be something done with the wording.

[gerblesh]

I agree that it is annoying to get the notification every 6 hours without fail. There could also be checks in place to only send the notification when an update for the image is found. The idea of the notifications was to have some way of telling the user that updates were running in the background. Appindicator might be one such solution, or something similar maybe?

[remggo]

Hey, I have seen that I have broke the tests. I will fix that and try to propose a solution that only Shows the notification if there is a System Upgrade.

The notification is not totally wrong as Flatpak updates and Distrobox Updates (via topgrade) could be considered System Updates. However, I would only show the notification if there is an update of the bluefin/aurora image itself, as that notification would nudge me to wait for the restart notification.

[remggo]

I have read the code a little bit more and actually the info if a system update is available gets passed into the function. I have added a test to see that no notifications are being sent if there is no system update.