Fixes shape mismatch in body COM randomization (#2561)

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Shape mismatched for randomised sample values in
randomize_rigid_body_com in `events.py.`

Fixes #2557 

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## Type of change

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- Bug fix (non-breaking change which fixes an issue) for #2557 

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---------

Signed-off-by: Dhananjay M Shendre <shendredm1999@gmail.com>
Signed-off-by: Mayank Mittal <12863862+Mayankm96@users.noreply.github.com>
Signed-off-by: DJ <shendredm1999@gmail.com>
Co-authored-by: Mayank Mittal <12863862+Mayankm96@users.noreply.github.com>

Author: shendredm

source/isaaclab/isaaclab/envs/mdp/events.py

@@ -380,9 +380,7 @@ def randomize_rigid_body_com(
     # sample random CoM values
     range_list = [com_range.get(key, (0.0, 0.0)) for key in ["x", "y", "z"]]
     ranges = torch.tensor(range_list, device="cpu")
-    rand_samples = math_utils.sample_uniform(
-        ranges[:, 0], ranges[:, 1], (len(env_ids), len(body_ids), 3), device="cpu"
-    ).unsqueeze(1)
+    rand_samples = math_utils.sample_uniform(ranges[:, 0], ranges[:, 1], (len(env_ids), 3), device="cpu").unsqueeze(1)
 
     # get the current com of the bodies (num_assets, num_bodies)
     coms = asset.root_physx_view.get_coms().clone()