Bump psycopg from 3.2.12 to 3.3.4 in /backend

Bumps [psycopg](https://github.com/psycopg/psycopg) from 3.2.12 to 3.3.4.
- [Changelog](https://github.com/psycopg/psycopg/blob/master/docs/news.rst)
- [Commits](psycopg/psycopg@3.2.12...3.3.4)

---
updated-dependencies:
- dependency-name: psycopg
  dependency-version: 3.3.4
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

backend/pyproject.toml

@@ -103,7 +103,7 @@ dependencies = [
     "ipython>=8.30.0",
     "weasyprint>=68.0",
     "opencv-python-headless>=4.10.0.84",
-    "psycopg[c]==3.2.12",
+    "psycopg[c]==3.3.4",
     "sentence-transformers>=3.0.0",
     # Declared directly so [tool.uv.sources] binds torch to the CPU index
     # (sources only apply to direct deps). Otherwise it's transitive via