feat(repositories/autoware.repos): minor update autowarefoundation/autoware_utils to 1.6.0 (#6840)

Signed-off-by: Mamoru Sobue <mamoru.sobue@tier4.jp>

Author: soblin

repositories/autoware.repos

@@ -19,7 +19,7 @@ repositories:
   core/autoware_utils:
     type: git
     url: https://github.com/autowarefoundation/autoware_utils.git
-    version: 1.5.0
+    version: 1.6.0
   core/autoware_lanelet2_extension:
     type: git
     url: https://github.com/autowarefoundation/autoware_lanelet2_extension.git