Bump matrix-js-sdk from 0.5.6 to 12.4.1

Bumps [matrix-js-sdk](https://github.com/matrix-org/matrix-js-sdk) from 0.5.6 to 12.4.1.
- [Release notes](https://github.com/matrix-org/matrix-js-sdk/releases)
- [Changelog](https://github.com/matrix-org/matrix-js-sdk/blob/develop/CHANGELOG.md)
- [Commits](https://github.com/matrix-org/matrix-js-sdk/compare/v0.5.6...v12.4.1)

---
updated-dependencies:
- dependency-name: matrix-js-sdk
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

package.json

@@ -20,6 +20,6 @@
   "dependencies": {
     "acorn": "^6.4.1",
     "matrix-appservice-bridge": "^2.6.1",
-    "matrix-js-sdk": "^0.5"
+    "matrix-js-sdk": "^12.4"
   }
 }