Update to Angular 20

[m-akinc]

Only rule changes are as follows:

• @angular-eslint/component-class-suffix removed (was error)
• @angular-eslint/directive-class-suffix removed (was error)

We also have a new recommended rule that we are disabling:

• @angular-eslint/prefer-inject
  Apparently, using the inject() function is recommended over injection as constructor arguments. Angular even provides an automatic migration (ng generate @angular/core:inject), but it's not smart. It just puts new fields immediately before the constructor, but they need to be declared/initialized before any other field initializers that depend on them. For automation purposes (and probably as general convention), that means we want them declared at the top of the class. @typescript-eslint/member-ordering doesn't have an automated fix-up, nor the ability to take initializers into acount. The Perfectionist sort-classes rule has both of those, so I optimistically tried using that instead. We can configure their rule to enforce (and automate the sorting of) fields initialized with inject(... coming before all other fields. But I wasn't able to prevent it from auto-sorting getter/setter pairs with different access modifiers apart from each other (which is also a violation).

Aside from this it's unclear how painful it would be to update unit test code that might be constructing these objects directly. Based on all this, I'm disabling the rule.