chore(deps): bump langfuse from 2.36.2 to 2.38.0 in /backend
Bumps [langfuse](https://github.com/langfuse/langfuse) from 2.36.2 to 2.38.0.
- [Release notes](https://github.com/langfuse/langfuse/releases)
- [Commits](https://github.com/langfuse/langfuse/commits/v2.38.0)
---
updated-dependencies:
- dependency-name: langfuse
dependency-type: direct:production
update-type: version-update:semver-minor
...
Signed-off-by: dependabot[bot] <support@github.com>