Bump sortablejs from 1.15.3 to 1.15.6

Bumps [sortablejs](https://github.com/SortableJS/Sortable) from 1.15.3 to 1.15.6.
- [Release notes](https://github.com/SortableJS/Sortable/releases)
- [Commits](SortableJS/Sortable@1.15.3...1.15.6)

---
updated-dependencies:
- dependency-name: sortablejs
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <support@github.com>

package.json

@@ -19,7 +19,7 @@
     "@types/uuid": "^10.0.0",
     "@vueuse/core": "^12.1.0",
     "@vueuse/integrations": "^11.0.0",
-    "sortablejs": "^1.15.2",
+    "sortablejs": "^1.15.6",
     "uuid": "^10.0.0",
     "vue": "^3.5.13"
   },