Remove @types/classnames package

`classnames` provides its own type definitions, so we do not need to
have this installed.

Author: koesie10

extensions/ql-vscode/package-lock.json

@@ -1974,7 +1974,6 @@
     "@testing-library/react": "^14.0.0",
     "@testing-library/user-event": "^14.4.3",
     "@types/child-process-promise": "^2.2.1",
-    "@types/classnames": "^2.2.9",
     "@types/d3": "^7.4.0",
     "@types/d3-graphviz": "^2.6.6",
     "@types/del": "^4.0.0",