refactor lib/private/Notification

[shdehnavi]

Summary

The required adjustments have been made to the classes in /lib/private/Notification namespace.

The improvements:

• Using PHP8's constructor property promotion
• Adding return types
• Adding types to properties

Checklist

• Code is properly formatted
• Sign-off message is added to all commits

[shdehnavi]

@blizzz All conflicts have been resolved, Ready to merge

[artonge]

Rebased to see if Cypress gets green. If not, can you try to check what's happening locally @shdehnavi?

[shdehnavi]

Rebased to see if Cypress gets green. If not, can you try to check what's happening locally @shdehnavi?

I often encounter errors in Cypress jobs with most of my pull requests. I have rebased the code but nothing changed, still the same as earlier.

@artonge

[artonge]

I often encounter errors in Cypress jobs with most of my pull requests. I have rebased the code but nothing changed, still the same as earlier.

The docker image was outdated, I released a new version, Cypress tests are now green :)

[artonge]

Looks like drone is not triggered. And the performance step looks not related. Merging