build: update trl requirement from <=0.21.0 to <=0.29.0

Updates the requirements on [trl](https://github.com/huggingface/trl) to permit the latest version.
- [Release notes](https://github.com/huggingface/trl/releases)
- [Changelog](https://github.com/huggingface/trl/blob/main/RELEASE.md)
- [Commits](huggingface/trl@v0.2.0...v0.29.0)

---
updated-dependencies:
- dependency-name: trl
  dependency-version: 0.29.0
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

pyproject.toml

@@ -145,7 +145,7 @@ dependencies = [
     "imageio-ffmpeg",
     "jaxtyping",
     "peft>=0.18.0",
-    "trl<=0.21.0",
+    "trl<=0.29.0",
     "termcolor==2.3.0",
 ]