Fix Zend_Form_ElementTest

The behaviour hasn't really changed because the intent of the test is to
use an array of arrays in setOptions. What has changed is that PHP 8.0
supports calling functions with named parameters and will throw a Fatal
if you try to access a parameter by name that does not exist.
Digits::__construct has no param named bar ergo we get a Fatal.

tests/Zend/Form/ElementTest.php

@@ -48,6 +48,11 @@
  */
 class Zend_Form_ElementTest extends PHPUnit_Framework_TestCase
 {
+    /**
+     * @var Zend_Form_Element
+     */
+    private $element;
+
     public static function main()
     {
         $suite  = new PHPUnit_Framework_TestSuite('Zend_Form_ElementTest');
@@ -1760,12 +1765,12 @@ public function testSetOptionsSetsArrayOfArrayFilters()
 
         $options = $this->getOptions();
         $options['filters'] = array(
-            array('Digits', array('bar' => 'baz')),
+            array('Alnum', array('allowWhiteSpace' => true)),
             array('Alpha', array('foo')),
         );
         $this->element->setOptions($options);
-        $filter = $this->element->getFilter('Digits');
-        $this->assertTrue($filter instanceof Zend_Filter_Digits);
+        $filter = $this->element->getFilter('Alnum');
+        $this->assertTrue($filter instanceof Zend_Filter_Alnum);
         $filter = $this->element->getFilter('Alpha');
         $this->assertTrue($filter instanceof Zend_Filter_Alpha);
     }