Regenerate spanner client (#6163)

Generated in GitHub action: https://togithub.com/googleapis/googleapis/google-api-php-client-services/actions/workflows/codegen.yaml

Author: yoshi-code-bot

src/Spanner/Backup.php

@@ -56,8 +56,6 @@ class Backup extends \Google\Collection
    * @var string
    */
   public $incrementalBackupChainId;
-  protected $instancePartitionsType = BackupInstancePartition::class;
-  protected $instancePartitionsDataType = 'array';
   /**
    * @var string
    */
@@ -231,20 +229,6 @@ public function getIncrementalBackupChainId()
   {
     return $this->incrementalBackupChainId;
   }
-  /**
-   * @param BackupInstancePartition[]
-   */
-  public function setInstancePartitions($instancePartitions)
-  {
-    $this->instancePartitions = $instancePartitions;
-  }
-  /**
-   * @return BackupInstancePartition[]
-   */
-  public function getInstancePartitions()
-  {
-    return $this->instancePartitions;
-  }
   /**
    * @param string
    */