Update xformers Channel and Version in environment.yml

[CREED404]

This pull request addresses a compatibility issue in the "demo/environment.yml" file:

• The current specification of the xformers package in the xformers/label/dev channel is causing conflicts with the required versions of dependencies such as cudatoolkit and pytorch.
• These conflicts prevent users from installing the required dependencies needed to run the GLIGEN demo with CUDA support.

To resolve this issue, the xformers package has been updated to use the correct channel (xformers) and has been set to version 0.0.22. This change ensures compatibility with the specified versions of cudatoolkit and pytorch.

The purpose of this update is to resolve the reported conflicts. The modifications made in the environment.yml file have undergone thorough testing to ensure a smooth installation process.

Please review and merge these changes at your earliest convenience. Feel free to reach out if further adjustments are needed. Thank you!

[iLori-Jiang]

It works for me! Thanks for your modification!