remove unnecessary BC coverage from generic type alias resolution

Amp-Thread-ID: https://ampcode.com/threads/T-01a19219-5899-7222-8fa0-6cb7e6fb7182

Author: shmax

src/PhpDoc/TypeNodeResolver.php

@@ -876,17 +876,8 @@ static function (string $variance): TemplateTypeVariance {
 		}
 
 		// Check for a generic type alias (e.g. MyList<string>) before falling through to
-		// class-based generic resolution, but only when the name is not itself a resolvable
-		// class — in that case the class-based path must win to preserve backward compatibility
-		// (a type alias like BelongsTo<T, U> = \Eloquent\BelongsTo<T, U> should still produce
-		// the same GenericObjectType that class-based resolution would have given).
-		$genericTypeAlias = null;
-		if ($typeNode->type instanceof IdentifierTypeNode) {
-			$resolvedGenericName = $nameScope->resolveStringName($typeNode->type->name);
-			$genericTypeAlias = !$this->getReflectionProvider()->hasClass($resolvedGenericName)
-				? $this->findGenericTypeAlias($typeNode->type->name, $nameScope)
-				: null;
-		}
+		// class-based generic resolution.
+		$genericTypeAlias = $typeNode->type instanceof IdentifierTypeNode ? $this->findGenericTypeAlias($typeNode->type->name, $nameScope) : null;
 		if ($genericTypeAlias !== null) {
 			$templateNodes = $genericTypeAlias->getTemplateTagValueNodes();
 			$totalParams = count($templateNodes);