fix SQLSRV throws for method_exists()

pdo_sqlsrv driver 5.9.0 throws an exception for any call on method_exists().
(see microsoft/msphpsql/issues/1306)
executeStatement() is a DBAL-method, exec() is PDO.
fix by excluding method_exists() check on PDO type of connections

Author: GDmac

Store/PdoStore.php

@@ -268,7 +268,7 @@ public function createTable(): void
             $table->setPrimaryKey([$this->idCol]);
 
             foreach ($schema->toSql($conn->getDatabasePlatform()) as $sql) {
-                if (method_exists($conn, 'executeStatement')) {
+                if ($conn instanceof Connection && method_exists($conn, 'executeStatement')) {
                     $conn->executeStatement($sql);
                 } else {
                     $conn->exec($sql);
@@ -298,7 +298,7 @@ public function createTable(): void
                 throw new \DomainException(sprintf('Creating the lock table is currently not implemented for PDO driver "%s".', $driver));
         }
 
-        if (method_exists($conn, 'executeStatement')) {
+        if ($conn instanceof Connection && method_exists($conn, 'executeStatement')) {
             $conn->executeStatement($sql);
         } else {
             $conn->exec($sql);
@@ -313,7 +313,7 @@ private function prune(): void
         $sql = "DELETE FROM $this->table WHERE $this->expirationCol <= {$this->getCurrentTimestampStatement()}";
 
         $conn = $this->getConnection();
-        if (method_exists($conn, 'executeStatement')) {
+        if ($conn instanceof Connection && method_exists($conn, 'executeStatement')) {
             $conn->executeStatement($sql);
         } else {
             $conn->exec($sql);