Use OCI_NO_AUTO_COMMIT instead of OCI_DEFAULT

This constant is not recognized by PHPStan, and besides the docs say
this:

> Prior to PHP 5.3.2 (PECL OCI8 1.4) use OCI_DEFAULT which is equivalent
to OCI_NO_AUTO_COMMIT.

See https://www.php.net/manual/en/function.oci-execute.php

lib/Doctrine/DBAL/Driver/OCI8/Driver.php

@@ -4,7 +4,7 @@ namespace Doctrine\DBAL\Driver\OCI8;
 
 use Doctrine\DBAL\DBALException;
 use Doctrine\DBAL\Driver\AbstractOracleDriver;
-use const OCI_DEFAULT;
+use const OCI_NO_AUTO_COMMIT;
 
 /**
  * A Doctrine DBAL driver for the Oracle OCI8 PHP extensions.
@@ -22,7 +22,7 @@ class Driver extends AbstractOracleDriver
                 (string) $password,
                 $this->_constructDsn($params),
                 $params['charset'] ?? '',
-                $params['sessionMode'] ?? OCI_DEFAULT,
+                $params['sessionMode'] ?? OCI_NO_AUTO_COMMIT,
                 $params['persistent'] ?? false
             );
         } catch (OCI8Exception $e) {

lib/Doctrine/DBAL/Driver/OCI8/OCI8Connection.php

@@ -7,7 +7,6 @@ use Doctrine\DBAL\Driver\ServerInfoAwareConnection;
 use Doctrine\DBAL\ParameterType;
 use UnexpectedValueException;
 use const OCI_COMMIT_ON_SUCCESS;
-use const OCI_DEFAULT;
 use const OCI_NO_AUTO_COMMIT;
 use function addcslashes;
 use function func_get_args;
@@ -51,7 +50,7 @@ class OCI8Connection implements Connection, ServerInfoAwareConnection
         $password,
         $db,
         $charset = '',
-        $sessionMode = OCI_DEFAULT,
+        $sessionMode = OCI_NO_AUTO_COMMIT,
         $persistent = false
     ) {
         $dbh = $persistent