Bump unstructured from 0.18.31 to 0.18.32 in /backend-agent

Bumps [unstructured](https://github.com/Unstructured-IO/unstructured) from 0.18.31 to 0.18.32.
- [Release notes](https://github.com/Unstructured-IO/unstructured/releases)
- [Changelog](https://github.com/Unstructured-IO/unstructured/blob/main/CHANGELOG.md)
- [Commits](Unstructured-IO/unstructured@0.18.31...0.18.32)

---
updated-dependencies:
- dependency-name: unstructured
  dependency-version: 0.18.32
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

Author: dependabot[bot]

backend-agent/pyproject.toml

@@ -26,7 +26,7 @@ dependencies = [
     'langchain-text-splitters>=0.3.0,<0.4.0',
     'PyYAML==6.0.3',
     'requests==2.32.5',
-    'unstructured==0.18.31',
+    'unstructured==0.18.32',
     'art==6.5',
     'pandas==2.3.3',
     'ollama==0.6.1',