fix: implement PhpDateTimeMappingType for TimestampType (#39377)

Author: J0sh0nat0r

src/Illuminate/Database/DBAL/TimestampType.php

@@ -4,9 +4,10 @@
 
 use Doctrine\DBAL\DBALException;
 use Doctrine\DBAL\Platforms\AbstractPlatform;
+use Doctrine\DBAL\Types\PhpDateTimeMappingType;
 use Doctrine\DBAL\Types\Type;
 
-class TimestampType extends Type
+class TimestampType extends Type implements PhpDateTimeMappingType
 {
     /**
      * {@inheritdoc}