Fixes typo in constructor for physics events (#217)

# Description

This MR fixes a bug introduced in #207 which was assigning tuples to the
`invalidate_handle` member in `AssetBase` and `SensorBase`.

## Type of change

<!-- As you go through the list, delete the ones that are not
applicable. -->

- Bug fix (non-breaking change which fixes an issue)

## Checklist

- [x] I have run the [`pre-commit` checks](https://pre-commit.com/) with
`./orbit.sh --format`
- [ ] I have made corresponding changes to the documentation
- [x] My changes generate no new warnings
- [ ] I have added tests that prove my fix is effective or that my
feature works
- [x] I have updated the changelog and the corresponding version in the
extension's `config/extension.toml` file

source/extensions/omni.isaac.orbit/config/extension.toml

 [package]
 
 # Note: Semantic Versioning is used: https://semver.org/
-version = "0.9.22"
+version = "0.9.23"
 
 # Description
 title = "ORBIT framework for Robot Learning"

source/extensions/omni.isaac.orbit/docs/CHANGELOG.rst

 Changelog
 ---------
 
+0.9.23 (2023-10-27)
+~~~~~~~~~~~~~~~~~~~
+
+Fixed
+^^^^^
+
+* Fixed a typo in the :class:`AssetBase` and :class:`SensorBase` that effected the class destructor.
+  Earlier, a tuple was being created in the constructor instead of the actual object.
+
+
 0.9.22 (2023-10-26)
 ~~~~~~~~~~~~~~~~~~~
 

source/extensions/omni.isaac.orbit/omni/isaac/orbit/assets/asset_base.py

@@ -57,18 +57,16 @@ class AssetBase(ABC):
         # note: Use weakref on all callbacks to ensure that this object can be deleted when its destructor is called.
         # add callbacks for stage play/stop
         # The order is set to 10 which is arbitrary but should be lower priority than the default order of 0
-        physx_interface = omni.physx.acquire_physx_interface()
-        self._initialize_handle = physx_interface.get_simulation_event_stream_v2().create_subscription_to_pop_by_type(
+        physx_event_stream = omni.physx.acquire_physx_interface().get_simulation_event_stream_v2()
+        self._initialize_handle = physx_event_stream.create_subscription_to_pop_by_type(
             int(omni.physx.bindings._physx.SimulationEvent.RESUMED),
             lambda event, obj=weakref.proxy(self): obj._initialize_callback(event),
             order=10,
         )
-        self._invalidate_initialize_handle = (
-            physx_interface.get_simulation_event_stream_v2().create_subscription_to_pop_by_type(
-                int(omni.physx.bindings._physx.SimulationEvent.STOPPED),
-                lambda event, obj=weakref.proxy(self): obj._invalidate_initialize_callback(event),
-                order=10,
-            ),
+        self._invalidate_initialize_handle = physx_event_stream.create_subscription_to_pop_by_type(
+            int(omni.physx.bindings._physx.SimulationEvent.STOPPED),
+            lambda event, obj=weakref.proxy(self): obj._invalidate_initialize_callback(event),
+            order=10,
         )
         # add callback for debug visualization
         if self.cfg.debug_vis:

source/extensions/omni.isaac.orbit/omni/isaac/orbit/sensors/sensor_base.py

@@ -54,18 +54,16 @@ class SensorBase(ABC):
         # note: Use weakref on callbacks to ensure that this object can be deleted when its destructor is called.
         # add callbacks for stage play/stop
         # The order is set to 10 which is arbitrary but should be lower priority than the default order of 0
-        physx_interface = omni.physx.acquire_physx_interface()
-        self._initialize_handle = physx_interface.get_simulation_event_stream_v2().create_subscription_to_pop_by_type(
+        physx_event_stream = omni.physx.acquire_physx_interface().get_simulation_event_stream_v2()
+        self._initialize_handle = physx_event_stream.create_subscription_to_pop_by_type(
             int(omni.physx.bindings._physx.SimulationEvent.RESUMED),
             lambda event, obj=weakref.proxy(self): obj._initialize_callback(event),
             order=10,
         )
-        self._invalidate_initialize_handle = (
-            physx_interface.get_simulation_event_stream_v2().create_subscription_to_pop_by_type(
-                int(omni.physx.bindings._physx.SimulationEvent.STOPPED),
-                lambda event, obj=weakref.proxy(self): obj._invalidate_initialize_callback(event),
-                order=10,
-            ),
+        self._invalidate_initialize_handle = physx_event_stream.create_subscription_to_pop_by_type(
+            int(omni.physx.bindings._physx.SimulationEvent.STOPPED),
+            lambda event, obj=weakref.proxy(self): obj._invalidate_initialize_callback(event),
+            order=10,
         )
         # add callback for debug visualization
         if self.cfg.debug_vis:

source/extensions/omni.isaac.orbit/test/assets/check_external_force.py

@@ -115,7 +115,7 @@ def main():
         robot.set_joint_position_target(robot.data.default_joint_pos.clone())
         robot.write_data_to_sim()
         # perform step
-        sim.step(render=app_launcher.RENDER)
+        sim.step()
         # update sim-time
         sim_time += sim_dt
         count += 1

source/extensions/omni.isaac.orbit/test/assets/test_articulation.py

@@ -147,7 +147,7 @@ class TestArticulation(unittest.TestCase):
                 robot.set_joint_position_target(robot.data.default_joint_pos.clone())
                 robot.write_data_to_sim()
                 # perform step
-                self.sim.step(render=app_launcher.RENDER)
+                self.sim.step()
                 # update buffers
                 robot.update(self.dt)
             # check condition that the robots have fallen down
@@ -194,7 +194,7 @@ class TestArticulation(unittest.TestCase):
                 robot.set_joint_position_target(robot.data.default_joint_pos.clone())
                 robot.write_data_to_sim()
                 # perform step
-                self.sim.step(render=app_launcher.RENDER)
+                self.sim.step()
                 # update buffers
                 robot.update(self.dt)
             # check condition