Fix failing test in CI

Author: SOHELAHMED7

src/SpecBaseObject.php

@@ -12,6 +12,7 @@
 use cebe\openapi\json\JsonPointer;
 use cebe\openapi\json\JsonReference;
 use cebe\openapi\spec\Reference;
+use cebe\openapi\spec\Schema;
 use cebe\openapi\spec\Type;
 
 /**
@@ -235,6 +236,9 @@ public function validate(): bool
         $this->_recursingValidate = true;
         $valid = true;
         $allowedFields = array_keys($this->attributes());
+        if (static::class === Schema::class) {
+            $allowedFields[] = 'additionalProperties';
+        }
         foreach ($this->_properties as $k => $v) {
             if ($allowedFields && !in_array($k, $allowedFields, true) && substr($k, 0, 2) !== 'x-') {
                 $valid = false;

tests/spec/PathTest.php

@@ -176,7 +176,6 @@ public function testPathItemReference()
         $this->assertInstanceOf(Response::class, $path200);
         $this->assertEquals('A bar', $path200->description);
 
-        unset($openapi);
         /** @var $openapi OpenApi */
         $openapi = Reader::readFromYamlFile($file, \cebe\openapi\spec\OpenApi::class, true);