[Improvement-18056] Remove unused code in tools module (#18116)

Author: SbloodyS

docs/configs/docsdev.js

@@ -474,10 +474,6 @@ export default {
                         title: 'Expansion and Reduction',
                         link: '/en-us/docs/dev/user_doc/guide/expansion-reduction.html',
                     },
-                    {
-                        title: 'Demo',
-                        link: '/en-us/docs/dev/user_doc/guide/demo.html',
-                    },
                 ],
             },
             {
@@ -1186,10 +1182,6 @@ export default {
                         title: '扩/缩容',
                         link: '/zh-cn/docs/dev/user_doc/guide/expansion-reduction.html',
                     },
-                    {
-                        title: 'Demo',
-                        link: '/zh-cn/docs/dev/user_doc/guide/demo.html',
-                    },
                 ],
             },
             {