test: Prove bug in AnnotationToAttributeRector with mixed content

If a file already contains a mix of annotations and attributes, the
current AnnotationToAttributeRector implementation drops the annotation
value when generating the new Attribute tag.

This could happen, for example, with a Behat context in a legacy project
that has a mix of old and new step definitions.

Author: acoulton

rules-tests/Php80/Rector/Class_/AnnotationToAttributeRector/Fixture/Behat/with_mixed_attribute_and_annotations.php.inc

@@ -0,0 +1,43 @@
+<?php
+
+namespace Rector\Tests\Php80\Rector\Class_\AnnotationToAttributeRector\Fixture\Behat;
+
+use Behat\Step\When;
+
+final class WithMixedAttributeAndAnnotations
+{
+    /**
+     * @When /^I have a step using annotations$/
+     */
+    public function hadAnnotations(): void
+    {
+    }
+
+    #[When('/^I have a step using attributes$/')]
+    public function hadAttributes(): void
+    {
+    }
+}
+
+?>
+-----
+<?php
+
+namespace Rector\Tests\Php80\Rector\Class_\AnnotationToAttributeRector\Fixture\Behat;
+
+use Behat\Step\When;
+
+final class WithMixedAttributeAndAnnotations
+{
+    #[\Behat\Step\When('/^I have a step using annotations$/')]
+    public function hadAnnotations(): void
+    {
+    }
+
+    #[When('/^I have a step using attributes$/')]
+    public function hadAttributes(): void
+    {
+    }
+}
+
+?>