Bump kolibri-tools from 0.15.0-dev.4 to 0.15.4

Bumps [kolibri-tools](https://github.com/learningequality/kolibri) from 0.15.0-dev.4 to 0.15.4.
- [Release notes](https://github.com/learningequality/kolibri/releases)
- [Changelog](https://github.com/learningequality/kolibri/blob/develop/CHANGELOG.md)
- [Commits](https://github.com/learningequality/kolibri/commits/v0.15.4)

---
updated-dependencies:
- dependency-name: kolibri-tools
  dependency-type: direct:development
  update-type: version-update:semver-patch
...

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

package.json

@@ -47,7 +47,7 @@
     "globby": "^6.1.0",
     "jest": "^27.4.7",
     "jest-serializer-vue": "^3.1.0",
-    "kolibri-tools": "0.15.0-dev.4",
+    "kolibri-tools": "0.15.4",
     "lockr": "^0.8.4",
     "material-design-icons": "^3.0.1",
     "mock-match-media": "^0.4.2",