Whenever a required input is accessed too early in a
directive/component, the signal input will throw an error.
This is necessary so that we can support required inputs
with intuitive typings that do not include `undefined` for
the short period of time where Angular is creating the component and
then assigning inputs later (Angular currently has no way of setting
inputs as part of the class creation when `new Dir()` happens)
PR Close#53808
