More class const improvements.

[AndrolGenhald]

Add InvalidClassConstType issue as alternative to LessSpecificClassConstType when type isn't contravariant.
Handle final class consts (#6395).
Use double quotes for types in class const issues.

Fixes #7668

[weirdan]

Can you add a test highlighting Psalm behaviour in regards to non-final interface constant inheritance? They were forbidden in PHP 5.0-8.0, and are allowed in PHP 8.1+: https://3v4l.org/PYZFB

[AndrolGenhald]

Can you add a test highlighting Psalm behaviour in regards to non-final interface constant inheritance? They were forbidden in PHP 5.0-8.0, and are allowed in PHP 8.1+: https://3v4l.org/PYZFB

Way ahead of you, that was added in #7154.

[psalm-github-bot]

I found these snippets:

https://psalm.dev/r/684e1851bf

<?php

interface A {
     const B = 1;
}

interface C extends A {
     const B = 2;
}

Psalm output (using commit 5aa06ae):

ERROR: OverriddenInterfaceConstant - 8:12 - C::B cannot override constant from A

INFO: LessSpecificClassConstantType - 8:12 - The type '2' for C::B is more general than the type '1' inherited from A::B

[weirdan]

Thanks!