Bump sortablejs from 1.15.0 to 1.15.3

Bumps [sortablejs](https://github.com/SortableJS/Sortable) from 1.15.0 to 1.15.3.
- [Release notes](https://github.com/SortableJS/Sortable/releases)
- [Commits](SortableJS/Sortable@1.15.0...1.15.3)

---
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

@@ -163,7 +163,7 @@
     "reflect-metadata": "^0.2.2",
     "rxjs": "^7.8.0",
     "sanitize-html": "^2.12.1",
-    "sortablejs": "1.15.0",
+    "sortablejs": "1.15.3",
     "uuid": "^8.3.2",
     "webfontloader": "1.6.28",
     "zone.js": "~0.14.4"