Python: Remove unused getTornadoRequestHandlerMethod

It was only used in a test, and with the mock, it gives no results anyway.

python/ql/src/semmle/python/web/tornado/Tornado.qll

@@ -11,10 +11,6 @@ ClassObject aTornadoRequestHandlerClass() {
     result.getASuperType() = theTornadoRequestHandlerClass()
 }
 
-FunctionObject getTornadoRequestHandlerMethod(string name) {
-    result = theTornadoRequestHandlerClass().declaredAttribute(name)
-}
-
 /** Holds if `node` is likely to refer to an instance of a tornado 
  * `RequestHandler` class.
  */