Cleanup and fix build

Signed-off-by: Alex Eftimie <alex.eftimie@getyourguide.com>

plugins/techdocs/package.json

@@ -73,7 +73,6 @@
     "@microsoft/fetch-event-source": "^2.0.1",
     "@types/react": "^16.13.1 || ^17.0.0 || ^18.0.0",
     "dompurify": "^3.0.0",
-    "event-source-polyfill": "1.0.25",
     "git-url-parse": "^14.0.0",
     "jss": "~10.10.0",
     "lodash": "^4.17.21",
@@ -91,7 +90,6 @@
     "@testing-library/react": "^15.0.0",
     "@testing-library/user-event": "^14.0.0",
     "@types/dompurify": "^3.0.0",
-    "@types/event-source-polyfill": "^1.0.0",
     "canvas": "^2.10.2"
   },
   "peerDependencies": {