remove some unused deps

Signed-off-by: Fredrik Adelöw <freben@gmail.com>

plugins/splunk-on-call/package.json

@@ -38,7 +38,6 @@
     "@backstage/core-components": "workspace:^",
     "@backstage/core-plugin-api": "workspace:^",
     "@backstage/plugin-catalog-react": "workspace:^",
-    "@backstage/theme": "workspace:^",
     "@material-ui/core": "^4.12.2",
     "@material-ui/icons": "^4.9.1",
     "@material-ui/lab": "4.0.0-alpha.61",
@@ -60,9 +59,7 @@
     "@testing-library/dom": "^9.0.0",
     "@testing-library/jest-dom": "^6.0.0",
     "@testing-library/react": "^14.0.0",
-    "@testing-library/user-event": "^14.0.0",
-    "@types/luxon": "^3.0.0",
-    "msw": "^1.0.0"
+    "@types/luxon": "^3.0.0"
   },
   "configSchema": "config.d.ts",
   "files": [