Which @angular/* package(s) are the source of the bug?

core

Is this a regression?

No

Description

inject()'s type description seems to be invalid:

Return type should be T | null only if flag is set to InjectFlags.Optional meaning that the signature should be something like this:

 export function ɵɵinject<T>(token: ProviderToken<T>): T; 
 export function ɵɵinject<T>(token: ProviderToken<T>, flags?: InjectFlags.Default | InjectFlags...): T; 
 export function ɵɵinject<T>(token: ProviderToken<T>, flags?: InjectFlags.Optional): T | null; 
 export function ɵɵinject<T>(token: ProviderToken<T>, flags = InjectFlags.Default): T|null

Please provide a link to a minimal reproduction of the bug

No response

Please provide the exception or error you saw

No response

Please provide the environment you discovered this bug in (run ng version)

No response

Anything else?

No response