update dependencies, remove @testing-library deps

remove the following two dependencies as they are currently not used
in the project:

* @testing-library/jest-dom
* @testing-library/react

Author: BenediktSeidl

package.json

@@ -13,12 +13,10 @@
   "author": "tribe29 GmbH",
   "license": "GPL-2.0-only",
   "devDependencies": {
-    "@grafana/data": "^8.5.4",
-    "@grafana/runtime": "^8.5.4",
-    "@grafana/toolkit": "^8.5.4",
-    "@grafana/ui": "^8.5.4",
-    "@testing-library/jest-dom": "5.16.4",
-    "@testing-library/react": "^12.1.5",
+    "@grafana/data": "^9.0.4",
+    "@grafana/runtime": "^9.0.4",
+    "@grafana/toolkit": "^9.0.4",
+    "@grafana/ui": "^9.0.4",
     "@types/lodash": "4.14.182"
   },
   "engines": {