TEMP: pin kolibri-design-system to KDS#1246 fork branch for review

Adds a `pnpm.overrides` entry pointing `kolibri-design-system` at the
fork branch backing the paired KDS PR (learningequality/kolibri-design-system#1246).
This lets reviewers `pnpm install` and immediately exercise the toolbar
with both Studio's learningequality#5707 changes AND the upstream KDS fix, instead of
needing to set up a `pnpm link` against a local KDS checkout.

REMOVE BEFORE MERGE:
- Delete the `kolibri-design-system` entry under `pnpm.overrides` in
  `package.json`.
- Bump the `kolibri-design-system` dependency version above to whatever
  KDS release ships with learningequality#1246 included.
- Run `pnpm install` to regenerate `pnpm-lock.yaml`.

This commit should be the first thing reverted/dropped once the KDS PR
is released.

Author: nucleogenesis

package.json

@@ -198,6 +198,9 @@
       "node-sass",
       "unrs-resolver",
       "vue-demi"
-    ]
+    ],
+    "overrides": {
+      "kolibri-design-system": "github:nucleogenesis/kolibri-design-system-1#studio/5258-rte--dynamic-width/klistwithoverflow-wrap-fix"
+    }
   }
 }