upgrade to laravel 7 and set branch to v2

vendor/symfony/http-foundation/Session/Storage/Handler/PdoSessionHandler.php

@@ -302,7 +302,7 @@ class PdoSessionHandler extends AbstractSessionHandler
     /**
      * {@inheritdoc}
      */
-    protected function doDestroy($sessionId)
+    protected function doDestroy(string $sessionId)
     {
         // delete the record associated with this id
         $sql = "DELETE FROM $this->table WHERE $this->idCol = :id";
@@ -323,7 +323,7 @@ class PdoSessionHandler extends AbstractSessionHandler
     /**
      * {@inheritdoc}
      */
-    protected function doWrite($sessionId, $data)
+    protected function doWrite(string $sessionId, string $data)
     {
         $maxlifetime = (int) ini_get('session.gc_maxlifetime');
 
@@ -606,11 +606,9 @@ class PdoSessionHandler extends AbstractSessionHandler
      * We need to make sure we do not return session data that is already considered garbage according
      * to the session.gc_maxlifetime setting because gc() is called after read() and only sometimes.
      *
-     * @param string $sessionId Session ID
-     *
-     * @return string The session data
+     * @return string
      */
-    protected function doRead($sessionId)
+    protected function doRead(string $sessionId)
     {
         if (self::LOCK_ADVISORY === $this->lockMode) {
             $this->unlockStatements[] = $this->doAdvisoryLock($sessionId);