chore: support numpy 2 (bump numpy, dm_control, mujoco)

[aditya-neuraco]

Relax numpy to >=2.0 and bump dm_control (>=1.0.43) and mujoco (>3) to versions that support numpy 2; the stale pyquaternion doesn't support 2.x comment is dropped (it does).

This unblocks the Neuracore Google Colab example, which runs bigym alongside neuracore and was failing because bigym pinned numpy<2 while neuracore requires numpy>=2. Import usage is unchanged.

Related PRs

• fix: remove trailing comma from pytest parametrize argnames #50 (remove trailing commas from pytest parametrize argnames) — should merge before all of these PyPI-prep PRs; it unblocks test collection on modern pytest (9.x).
• fix: migrate to upstream gymnasium 1.0 #52 (migrate to upstream gymnasium 1.0) — merge before this; the old gymnasium fork does not support numpy 2.
• chore: switch mojo dependency to PyPI mojo-mujoco-wrapper #51 (switch mojo dependency to PyPI) — related PyPI-prep step; no ordering dependency.

[stepjam]

LGTM w/c.

I'll assume you have tested that these works nicely together, as I assume the pinned dm_control version was for a reason.