Describe the bug

Running SteamVR 2.1.8. I get the warning

Thu Nov 23 2023 23:55:26.444147 [Info] - Determined this is a legacy app.
Thu Nov 23 2023 23:55:26.445461 [Info] - Determined this is a legacy app.
Thu Nov 23 2023 23:55:26.445662 [Info] - Unable to find input 'z' in filter click_button_actions_legacy_17_user_hand_left_input_thumbstick
Thu Nov 23 2023 23:55:26.445703 [Info] - Unable to find input 'z' in filter click_button_actions_legacy_18_user_hand_right_input_thumbstick
...

repeated over and over (many many times a second) in my vrclient_steam.txt log.

The spamming of the log files has already been reported in at least #307, #326, and #365, so I am not duplicating those. Rather I wanted to point out that Unable to find input 'z' in filter... bit appears to be caused by the force_input parameter for the left and right hand (only showing left here) .../input/thumbstick entries in legacy_bindings_index_controller.json (or, at least, removing these stops the Unable to find input 'z' in filter... portion of the logging).

            {
               "inputs" : {
                  "click" : {
                     "output" : "/actions/legacy/in/left_axis0_press"
                  }
               },
               "mode" : "button",
               "type" : "boolean_threshold",
               "parameters" : 
               {
	          "force_input" : "position",
                  "click_activate_threshold" : 0.8,
                  "click_deactivate_threshold" : 0.7,
		  "haptic_amplitude" : 0
               },
               "path" : "/user/hand/left/input/thumbstick"
            },

I would guess this is because the corresponding /input/thumbstick entry in the index_controller_profile.json file has no "force" : "true" item.

    "/input/thumbstick" : {
      "type" : "joystick",
      "click" : true,
      "touch" : true,
      "binding_image_point" : [ 31, 26 ],
      "order" : 4
    },

Probably it should have that instead of (or in addition to) "touch" : "true" or the former should have specified touch_... related parameters instead of force_... ones.

To Reproduce

Steps to reproduce the behavior:

1. Start SteamVR
2. Turn on an index controller.
3. Observe the vrclient_steam.log file.

Expected behavior
Shouldn't be getting this error.

System Information (please complete the following information):

• Distribution: NixOS
• SteamVR version: 2.1.7
• Steam client version: 1700160213 (Steam Client Build Date: Thu, Nov 16 1:23 PM UTC -08:00)
• Opted into Steam client beta?: No
• Graphics driver version: Mesa 23.1.9
• Gist for SteamVR System Information: SteamVR system info dump]

Screenshots

Additional context

Note: Commenters who are also experiencing this issue are encouraged to include the "System Information" section in their replies.