Support PHP 8.3 Override attribute

[edsrzf]

Psalm should support PHP 8.3's new Override attribute in two ways:

• When a method has an Override attribute but does not override a parent method, raise an issue. (Any method with an Override attribute that would cause a fatal runtime error should also be detected statically by Psalm.) Call it InvalidOverride. (Implemented in New InvalidOverride issue for Override attribute #10644.)
• When a method of a child class overrides that of a parent class and there is no Override attribute, raise an issue. Call it MissingOverrideAttribute.

Both of these would apply only when the PHP version is >= 8.3, and the second one should probably have its own configuration option.

I'm happy to work on the implementation and use this issue to track progress, discuss the ideas, and hash out any details, like the error names or configuration.

[psalm-github-bot]

Hey @edsrzf, can you reproduce the issue on https://psalm.dev? These will be used as phpunit tests when implementing the feature or fixing this bug.

[weirdan]

Don't we have that already? See #10493

[weirdan]

Maybe call it InvalidOverrideAttribute?

Just InvalidOverride would seem more fitting - as there's nothing wrong with the attribute itself.

Maybe call it MissingOverrideAttribute?

Sounds good to me.

[weirdan]

Don't we have that already? See #10493

That PR just adds the attribute stub.