fix: resolve static/self/parent relative to @param-closure-this bound class

[calebdw]

Bug

When a closure or arrow function has its $this type overridden via @param-closure-this, the static/self/parent keywords in return type declarations resolve to the enclosing class instead of the bound class.

Reproducer

final class CollectionMacros
{
    public static function boot(): void
    {
        Collection::macro(
            'asValueLabel',
            // PHPStan errors with:
            // Anonymous function should return static(\...\CollectionMacros)
            // but returns Illuminate\Support\Collection<int, array<string, mixed>>
            fn (): static => $this->map(fn ($l, $v) => ['value' => $v, 'label' => $l])->values(),
        );
    }
}

Where Collection::macro() has @param-closure-this static $macro, PHPStan correctly resolves $this inside the closure to Collection, but the static return type still resolves to CollectionMacros (the enclosing class) instead of Collection.

Root Cause

Two layers:

1. inClosureBindScopeClasses was never set when @param-closure-this was applied. NodeScopeResolver only called assignVariable('this', ...) to change the $this type, but did not set inClosureBindScopeClasses — which is what resolveTypeByName checks when resolving static/self/parent keywords.

2. getFunctionType used the enclosing class to resolve static in return type declarations. The closure's return type static went through InitializerExprTypeResolver::getFunctionType → ParserNodeTypeToPHPStanType::resolve, which used InitializerExprContext::fromScope($this) — always returning the enclosing class via $scope->getClassReflection().

Fix

src/Analyser/NodeScopeResolver.php

After assignVariable('this', ...), chain ->withClosureBindScopeClasses(...) so static/self resolve to the closure-this class. Applied to both closure and arrow function paths.

src/Analyser/MutatingScope.php

• withClosureBindScopeClasses() (new method): Creates a new scope with inClosureBindScopeClasses set, preserving all other state.
• restoreThis(): Restore inClosureBindScopeClasses from the saved scope (was using $this->, now uses $restoreThisScope->).
• getFunctionType(): When inClosureBindScopeClasses is set and the type is static/self/parent, pass a context with the bound class to InitializerExprTypeResolver so the return type resolves correctly.