[11.x] Deprecate Factory::$modelNameResolver (#54736)

Instead of removing the `$modelNameResolver` property entirely, which breaks any user-land and 3rd-party uses of it, this re-introduces the original property, but marks it as deprecated so that developers have a chance to migrate correctly without having to avoid other Laravel updates.

Author: samlev

src/Illuminate/Database/Eloquent/Factories/Factory.php

@@ -113,6 +113,13 @@ abstract class Factory
  */
  public static $namespace = 'Database\\Factories\\';
 
+ /**
+ * @deprecated use $modelNameResolvers
+ *
+ * @var callable(self): class-string<TModel>
+ */
+ protected static $modelNameResolver;
+
  /**
  * The default model name resolvers.
  *
@@ -810,7 +817,7 @@ public function modelName()
  return $this->model;
  }
 
- $resolver = static::$modelNameResolvers[static::class] ?? static::$modelNameResolvers[self::class] ?? function (self $factory) {
+ $resolver = static::$modelNameResolvers[static::class] ?? static::$modelNameResolvers[self::class] ?? static::$modelNameResolver ?? function (self $factory) {
  $namespacedFactoryBasename = Str::replaceLast(
  'Factory', '', Str::replaceFirst(static::$namespace, '', $factory::class)
  );
@@ -931,6 +938,7 @@ protected static function appNamespace()
  */
  public static function flushState()
  {
+ static::$modelNameResolver = null;
  static::$modelNameResolvers = [];
  static::$factoryNameResolver = null;
  static::$namespace = 'Database\\Factories\\';