Update fastapi requirement

Updates the requirements on [fastapi](https://github.com/fastapi/fastapi) to permit the latest version.
- [Release notes](https://github.com/fastapi/fastapi/releases)
- [Commits](fastapi/fastapi@0.115.12...0.121.0)

---
updated-dependencies:
- dependency-name: fastapi
  dependency-version: 0.121.0
  dependency-type: direct:production
...

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Author: dependabot[bot]

pyproject.toml

@@ -38,7 +38,7 @@ dependencies = [
     "elasticsearch~=7.9.1",
     "elasticsearch-dsl~=7.4.1",
     "expiringdict~=1.2",
-    "fastapi>=0.115.12,<0.121.0",
+    "fastapi>=0.115.12,<0.122.0",
     "flasgger~=0.9.7",
     "flask~=3.1",
     "flask-restful~=0.3.10",