Static function return type loses template in traits

[SCIF]

Version I found this behaviour: 4.20

https://psalm.dev/r/d68f60cae1

[psalm-github-bot]

I found these snippets:

https://psalm.dev/r/d68f60cae1

<?php

/** @template T */
trait B {
    /** @return array<T> */
    public function all() {return [];}
    
    /** @return array<T> */
    public static function statAll() {return [];}
}

class A {
    /** @use B<A> */
    use B;
}

$var = (new A)->all();
/** @psalm-trace $var */;

$var2 = A::statAll();
/** @psalm-trace $var2 */;

Psalm output (using commit 6af3b50):

INFO: Trace - 18:25 - $var: array<array-key, A>

INFO: Trace - 21:26 - $var2: array<array-key, never>

INFO: UnusedVariable - 17:1 - $var is never referenced or the value is not used

INFO: UnusedVariable - 20:1 - $var2 is never referenced or the value is not used

[AndrolGenhald]

Same root problem as #5753, static functions currently don't allow templates. Maybe we should add an InvalidDocblock error when it's attempted until we actually support it?