Remove update_data function from BaseBlock.php

This was not used

src/Blocks/BaseBlock.php

@@ -57,23 +57,6 @@ public static function is_rest_request(): bool
         return defined('REST_REQUEST') && REST_REQUEST;
     }
 
-    /**
-     * Update the attributes of a block to the latest version.
-     * It returns an array with the new version of the block attributes.
-     * PHPCS does not allow me to add the return type if there is no return statement, but here we always throw an
-     * exception, so adding a return after triggers another CS rule. Disabling the violated rule,
-     * Squiz.Commenting.FunctionComment.InvalidNoReturn, is not working in the doc comment.
-     *
-     * @param array $attributes The old version of the block attributes.
-     * @throws NotImplemented If no implementation is given by the subclass.
-     * @phpcs:disable SlevomatCodingStandard.Functions.UnusedParameter.UnusedParameter
-     */
-    public static function update_data(array $attributes): array
-    {
-        throw new NotImplemented('Method update_data is not implemented for ' . static::class);
-    }
-    //phpcs:enable SlevomatCodingStandard.Functions.UnusedParameter.UnusedParameter
-
     /**
      * Returns the block name with its namespace prefix, e.g.: planet4-blocks/accordion.
      */