build(deps-dev): bump unstructured from 0.18.14 to 0.18.32 in /backend

Bumps [unstructured](https://github.com/Unstructured-IO/unstructured) from 0.18.14 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@unstructured_0.18.14...0.18.32)

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

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

Author: dependabot[bot]

backend/pyproject.toml

@@ -25,7 +25,7 @@ data-process = [
     "celery>=5.3.6",
     "flower>=2.0.1",
     "nest_asyncio>=1.5.6",
-    "unstructured[csv,docx,pdf,pptx,xlsx,md]==0.18.14",
+    "unstructured[csv,docx,pdf,pptx,xlsx,md]==0.18.32",
     "huggingface_hub>=0.19.0,<0.21.0"
 ]
 test = [