Revert "Make Robolab Table Backgrounds Kinematic" (#1185)

Reverts #1179

<img width="1281" height="712" alt="image"
src="https://github.com/user-attachments/assets/d4e8492a-f056-456b-9329-bbfb8e8e0fa7"
/>

Author: xyao-nv

docs/pages/concepts/scene/concept_assets_design.rst

@@ -87,32 +87,6 @@ ownership away from the background.
 Instanceable subtrees that contribute dynamic physics are materialized at spawn
 time because physics views cannot control dynamic instance proxies.
 
-Rigid-body behavior
-^^^^^^^^^^^^^^^^^^^
-
-A background's ``BASE`` type does not remove physics authored in its USD. The
-``rigid_props`` value in ``spawn_cfg_addon`` is forwarded to Isaac Lab's USD spawner.
-When ``rigid_props=None`` (the default), the spawner does not add or modify rigid-body
-properties. A prim that already has ``UsdPhysics.RigidBodyAPI`` therefore keeps its
-authored behavior; for example, an authored dynamic body can move when gravity or
-contact forces act on it.
-
-For a background fixture that must not move, such as a table used only as a fixed
-work surface, make its rigid bodies kinematic:
-
-.. code-block:: python
-
-   spawn_cfg_addon = {
-       "rigid_props": sim_utils.RigidBodyPropertiesCfg(kinematic_enabled=True),
-   }
-
-A kinematic body still collides with dynamic objects, but gravity, forces, and contacts
-do not displace it. Its pose changes only when it is explicitly commanded. Do not use
-this setting when the background should respond physically. For example, a table that
-a humanoid is expected to push must remain dynamic: retain ``rigid_props=None`` when
-the USD already authors it as dynamic, or explicitly set ``kinematic_enabled=False``
-to override an authored kinematic setting.
-
 Object references
 -----------------
 

isaaclab_arena/assets/background_library.py

@@ -205,9 +205,6 @@ class MapleTableRobolab(LibraryBackground):
     tags = ["background", "robolab"]
     usd_path = f"{ARENA_NUCLEUS_DIR}/Arena/assets/object_library/srl_robolab_assets/scenes/maple_table.usda"
     object_min_z = -0.05
-    spawn_cfg_addon = {
-        "rigid_props": sim_utils.RigidBodyPropertiesCfg(kinematic_enabled=True),
-    }
 
 
 @register_asset
@@ -216,9 +213,6 @@ class TableOakRobolab(LibraryBackground):
     tags = ["background", "robolab"]
     usd_path = f"{ARENA_NUCLEUS_DIR}/Arena/assets/object_library/srl_robolab_assets/fixtures/table_oak.usd"
     object_min_z = -0.05
-    spawn_cfg_addon = {
-        "rigid_props": sim_utils.RigidBodyPropertiesCfg(kinematic_enabled=True),
-    }
 
 
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