Update keystoneauth1 requirement from ~=5.1.0 to ~=5.9.1

Updates the requirements on [keystoneauth1](https://docs.openstack.org/keystoneauth/latest/) to permit the latest version.

---
updated-dependencies:
- dependency-name: keystoneauth1
  dependency-type: direct:production
...

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

requirements.txt

@@ -14,6 +14,6 @@ cryptography~=43.0.1
 uvicorn~=0.30.6
 fastapi~=0.101.0
 pydantic~=2.9.2
-keystoneauth1~=5.1.0
+keystoneauth1~=5.9.1
 filelock~=3.16.1
 schema~=0.7.7