Remove deprecated await on proc_mesh/spawn calls in examples (#1406)

Summary:
Pull Request resolved: #1406

Fix Monarch examples broken by removal of DeprecatedNotAFuture in D82835567.

D82835567 removed the `DeprecatedNotAFuture` compatibility shim that provided fake `__await__()` methods on `ProcMesh` and `ActorMesh` objects.

With the shim removal, these examples started failing with:
```
TypeError: object ActorMesh can't be used in 'await' expression
```

This diff removes the incorrect `await` keywords.

Reviewed By: dulinriley

Differential Revision: D83138346

fbshipit-source-id: 83b32110c5e68b180c593499684936ae5cc6ce9d

Author: samhsia

docs/source/examples/ping_pong.py

@@ -43,7 +43,7 @@ async def hello_world(self, msg):
 async def create_toy_actors():
     local_proc_mesh = proc_mesh(gpus=NUM_ACTORS)
     # This spawns 4 instances of 'ToyActor'
-    toy_actor = await local_proc_mesh.spawn("toy_actor", ToyActor)
+    toy_actor = local_proc_mesh.spawn("toy_actor", ToyActor)
     return toy_actor, local_proc_mesh
 
 
@@ -100,14 +100,14 @@ async def recv(self, msg):
 async def create_ping_pong_actors():
     # Spawn two different Actors in different meshes, with two instances each
     local_mesh_0 = proc_mesh(gpus=2)
-    actor_0 = await local_mesh_0.spawn(
+    actor_0 = local_mesh_0.spawn(
         "actor_0",
         ExampleActor,
         "actor_0",  # this arg is passed to ExampleActor.__init__
     )
 
     local_mesh_1 = proc_mesh(gpus=2)
-    actor_1 = await local_mesh_1.spawn(
+    actor_1 = local_mesh_1.spawn(
         "actor_1",
         ExampleActor,
         "actor_1",  # this arg is passed to ExampleActor.__init__