[11.x] Fix $fail closure type in docblocks for validation rules

[bastien-phi]

Fixes the closure type as defined in

framework/src/Illuminate/Validation/InvokableValidationRule.php

Lines 102 to 106 in 7a3166c

	$this->invokable->{$method}($attribute, $value, function ($attribute, $message = null) {
	$this->failed = true;
	return $this->pendingPotentiallyTranslatedString($attribute, $message);
	});