Update pydantic requirement from ~=2.1.1 to ~=2.9.1

Updates the requirements on [pydantic](https://github.com/pydantic/pydantic) to permit the latest version.
- [Release notes](https://github.com/pydantic/pydantic/releases)
- [Changelog](https://github.com/pydantic/pydantic/blob/main/HISTORY.md)
- [Commits](pydantic/pydantic@v2.1.1...v2.9.1)

---
updated-dependencies:
- dependency-name: pydantic
  dependency-type: direct:production
...

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

requirements.txt

@@ -13,7 +13,7 @@ seedir~=0.4.2
 cryptography~=38.0.4
 uvicorn~=0.23.2
 fastapi~=0.101.0
-pydantic~=2.1.1
+pydantic~=2.9.1
 keystoneauth1~=5.1.0
 filelock~=3.13.1
 schema~=0.7.7