fix: enable/disable 'update all' button correctly
Description
Correctly enable/disable "Update all" button in update screen.
Screenshots
Technical details
The “Update All” button state was being updated from multiple places, which caused UI glitches. As a result, it sometimes appeared enabled when it shouldn’t have been, and at other times it wasn’t re-enabled when it should have been (for example, after a manually triggered “Update All” job completed). This logic has now been consolidated into a single block of code, ensuring the button state is updated correctly and consistently instead of being modified randomly from different places.
Tests
Issues
https://gitlab.e.foundation/e/os/backlog/-/issues/3943