Update src/SchemaModel.php

Co-authored-by: Jason Adams <jason.adams@stellarwp.com>

Author: dpanta94

src/SchemaModel.php

@@ -537,7 +537,7 @@ private function deleteAllRelationshipData(): void {
 	 *
 	 * @param string  $key                 The key of the relationship.
 	 * @param string  $type                The type of the relationship.
-	 * @param ?string $through             A table interface that provides the relationship.
+	 * @param ?class-string<Table_Interface> $through             A table interface that provides the relationship.
 	 * @param string  $relationship_entity The entity of the relationship.
 	 */
 	protected function defineRelationship( string $key, string $type, ?string $through = null, string $relationship_entity = 'post' ): void {