Bump sortablejs from 1.15.4 to 1.15.6 in /ui (#703)

Bumps [sortablejs](https://github.com/SortableJS/Sortable) from 1.15.4 to 1.15.6.
- [Release notes](https://github.com/SortableJS/Sortable/releases)
- [Commits](SortableJS/Sortable@1.15.4...1.15.6)

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

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

ui/core/package.json

@@ -39,7 +39,7 @@
     "moment": "^2.30.1",
     "popper.js": "^1.14.4",
     "sass": "^1.81.0",
-    "sortablejs": "^1.15.4",
+    "sortablejs": "^1.15.6",
     "tippy.js": "^6.3.7",
     "underscore": "^1.13.7",
     "v-tooltip": "^2.0.0-rc.33",

ui/wallet/package.json

@@ -30,7 +30,7 @@
     "moment": "^2.30.1",
     "popper.js": "^1.14.4",
     "sass": "^1.81.0",
-    "sortablejs": "^1.15.4",
+    "sortablejs": "^1.15.6",
     "tippy.js": "^6.3.7",
     "truffle-assertions": "^0.9.1",
     "typeahead": "^0.2.2",

ui/yarn.lock

@@ -11109,10 +11109,10 @@ [email protected]:
   resolved "https://registry.yarnpkg.com/sortablejs/-/sortablejs-1.10.2.tgz#6e40364d913f98b85a14f6678f92b5c1221f5290"
   integrity sha512-YkPGufevysvfwn5rfdlGyrGjt7/CRHwvRPogD/lC+TnvcN29jDpCifKP+rBqf+LRldfXSTh+0CGLcSg0VIxq3A==
 
-sortablejs@^1.15.4:
-  version "1.15.4"
-  resolved "https://registry.yarnpkg.com/sortablejs/-/sortablejs-1.15.4.tgz#f5601f6aa725df1601c09a4a50a8f4ea5d95d96b"
-  integrity sha512-wr7G5Id/WNllca5yF9I2vsz/2wDKJebX5FJBtfUFBGGpaaIVjW4kziAnNMEcigaTZAaPLB92NYBGqWenGDH++g==
+sortablejs@^1.15.6:
+  version "1.15.6"
+  resolved "https://registry.yarnpkg.com/sortablejs/-/sortablejs-1.15.6.tgz#ff93699493f5b8ab8d828f933227b4988df1d393"
+  integrity sha512-aNfiuwMEpfBM/CN6LY0ibyhxPfPbyFeBTYJKCvzkJ2GkUpazIt3H+QIPAMHwqQ7tMKaHz1Qj+rJJCqljnf4p3A==
 
 source-list-map@^2.0.0:
   version "2.0.1"