Remove redundant ws dependency

`socket.io` already depends on `ws` and uses it by default.
The separate dependency to and initialization of `ws` sees to be
a relic of the past usage of `uws`, but is redundant now.

As documented in https://socket.io/docs/v2/server-initialization/#Notable-options,
`perMessageDeflate` is now `false` by default.

Signed-off-by: David Mehren <git@herrmehren.de>

package.json

@@ -103,7 +103,6 @@
     "uuid": "^8.0.0",
     "validator": "^13.0.0",
     "winston": "^3.1.0",
-    "ws": "^7.4.4",
     "xss": "^1.0.3"
   },
   "resolutions": {