chore(deps): update openai requirement in /store/backend

Updates the requirements on [openai](https://github.com/openai/openai-python) to permit the latest version.
- [Release notes](https://github.com/openai/openai-python/releases)
- [Changelog](https://github.com/openai/openai-python/blob/main/CHANGELOG.md)
- [Commits](openai/openai-python@v1.106.0...v2.3.0)

---
updated-dependencies:
- dependency-name: openai
  dependency-version: 2.3.0
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

store/backend/pyproject.toml

@@ -40,7 +40,7 @@ dependencies = [
     "orjson~=3.8",
     "flask_orjson~=2.0.0",
     "pgvector~=0.4",
-    "openai~=1.106",
+    "openai~=2.3",
     "tenacity~=9.1",
 ]