message: plugin-api: tweak dependencies
diff: "@backstage/config": "^0.1.3",
  "@backstage/theme": "^0.2.3",
  "@types/react": "^16.9",
  - "@types/prop-types": "^15.7.3",
  "history": "^5.0.0",
  "prop-types": "^15.7.2",
  "react": "^16.12.0",
  "@testing-library/user-event": "^13.1.8",
  "@types/jest": "^26.0.7",
  "@types/node": "^14.14.32",
  + "@types/prop-types": "^15.7.3",
  "@types/zen-observable": "^0.8.0",
  "cross-fetch": "^3.0.6",
  "msw": "^0.21.3"
  