Remove lock around tokio-rt handle (#36762)

It seems sub-optimal to to sequentialise execution by grabbing a lock,
each time we want to spawn a task onto the tokio runtime. We don't need
the lock either, so it makes sense to just remove it, which also
simplifies a bunch of the using code.

Testing: Covered by existing tests

Signed-off-by: Jonathan Schwender <schwenderjonathan@gmail.com>

components/net/connector.rs

@@ -165,7 +165,7 @@ where
     F: Future<Output = ()> + 'static + std::marker::Send,
 {
     fn execute(&self, fut: F) {
-        HANDLE.lock().unwrap().as_ref().unwrap().spawn(fut);
+        HANDLE.spawn(fut);
     }
 }