Update gymnasium dependency to version 1.2.1 (#3696)

# Description

This MR updates gymnasium version to prevent memory leak while video
recording.

Related MR: https://github.com/Farama-Foundation/Gymnasium/pull/1444

Fixes https://github.com/isaac-sim/IsaacLab/pull/3387


## Type of change

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

## Checklist

- [x] I have read and understood the [contribution
guidelines](https://isaac-sim.github.io/IsaacLab/main/source/refs/contributing.html)
- [x] I have run the [`pre-commit` checks](https://pre-commit.com/) with
`./isaaclab.sh --format`
- [ ] I have made corresponding changes to the documentation
- [x] My changes generate no new warnings
- [ ] I have added tests that prove my fix is effective or that my
feature works
- [ ] I have updated the changelog and the corresponding version in the
extension's `config/extension.toml` file
- [x] I have added my name to the `CONTRIBUTORS.md` or my name already
exists there
Signed-off-by: Mayank Mittal <12863862+Mayankm96@users.noreply.github.com>
Co-authored-by: ooctipus <zhengyuz@nvidia.com>

source/isaaclab/setup.py

@@ -26,7 +26,7 @@ INSTALL_REQUIRES = [
     # devices
     "hidapi==0.14.0.post2",
     # reinforcement learning
-    "gymnasium==1.2.0",
+    "gymnasium==1.2.1",
     # procedural-generation
     "trimesh",
     "pyglet<2",