Bump fastapi from 0.121.2 to 0.121.3

Bumps [fastapi](https://github.com/fastapi/fastapi) from 0.121.2 to 0.121.3.
- [Release notes](https://github.com/fastapi/fastapi/releases)
- [Commits](fastapi/fastapi@0.121.2...0.121.3)

---
updated-dependencies:
- dependency-name: fastapi
  dependency-version: 0.121.3
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

Author: dependabot[bot]

requirements.txt

@@ -1,5 +1,5 @@
 couchbase==4.5.0
-fastapi==0.121.2
+fastapi==0.121.3
 httpx==0.28.1
 pydantic==2.12.4
 pydantic_settings==2.12.0