Remove @jupyterlab/launcher dependency

Co-authored-by: Michał Krassowski <[email protected]>

Author: davidbrochart

packages/labextension/package.json

@@ -45,7 +45,6 @@
     "@jupyterlab/application": "^3.5.1",
     "@jupyterlab/apputils": "^3.5.1",
     "@jupyterlab/coreutils": "^5.5.1",
-    "@jupyterlab/launcher": "^3.5.1",
     "@jupyterlab/notebook": "^3.5.1",
     "@jupyterlab/services": "^6.5.1",
     "@jupyterlab/statusbar": "^3.5.1",