Exception is printed because there are no null checks for Ray Interactor when its value is removed from ActionBasedControllerManager Component

Steps to reproduce:
1. Open the attached user's project "TestXRI.rar"
2. Under "Assets/Samples/XR Interaction Toolkit/2.3.1/Starter Assets/DemoScene.unity" open the Scene
3. Under "Complete XR Origin Set up" GameObject make sure that Ray Interactor GameObject is disabled under the "LeftHand" GameObject
4. Remove Ray Interactor value from the "ActionBasedControllerManager" Component under the "LeftHand" GameObject
5. Remove the Ray Interactor value from "XR interaction group" Component under the "LeftHand" GameObject
6. Connect the Oculus link and enter Play Mode
7. Observe the exception:
ArgumentNullException: Value cannot be null
Parameter name: groupMember

Expected results: Exception is not printed and null checks are present for Ray Interactor
Actual Results: Exception is printed because there are no null checks for Ray Interactor

Reproducible in: XRIT 2.3.1, 2.3.2 (2020.3.48f1, 2021.3.25f1, 2022.2.18f1, 2023.1.0b16, 2023.2.0a14)

Notes:
-Null checks are missing in Start() when compared to DirectInteractor.cs (lines 248, 260)