Bump sortablejs from 1.15.0 to 1.15.1 in /src/dispatch/static/dispatch

Bumps [sortablejs](https://github.com/SortableJS/Sortable) from 1.15.0 to 1.15.1.
- [Release notes](https://github.com/SortableJS/Sortable/releases)
- [Commits](SortableJS/Sortable@1.15.0...1.15.1)

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

Signed-off-by: dependabot[bot] <[email protected]>