add benchmark: bimanual arm scene with more objects

[thowell]

the existing bimanual arm scene benchmarks have 1 object. we should add a bimanual arm benchmark with more objects to better evaluate performance for:

• many dofs
• many constraints
• cg solver
• sparsity

[Aaryan-549]

Hi @thowell, I'd like to take over this issue. I can work on adding the bimanual arm benchmark with multiple objects to improve the evaluation. Could you please assign it to me?

[thowell]

@Aaryan-549 the mujoco warp team will add this benchmark. thanks!

[Aaryan-549]

Sounds good! Happy to help.