build(deps): bump fastmcp from 2.12.0 to 3.1.1 in /backend

Bumps [fastmcp](https://github.com/PrefectHQ/fastmcp) from 2.12.0 to 3.1.1.
- [Release notes](https://github.com/PrefectHQ/fastmcp/releases)
- [Changelog](https://github.com/PrefectHQ/fastmcp/blob/main/docs/changelog.mdx)
- [Commits](PrefectHQ/fastmcp@v2.12.0...v3.1.1)

---
updated-dependencies:
- dependency-name: fastmcp
  dependency-version: 3.1.1
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

Author: dependabot[bot]

backend/pyproject.toml

@@ -14,7 +14,7 @@ dependencies = [
     "pyyaml>=6.0.2",
     "ruamel-yaml==0.19.1",
     "redis>=5.0.0",
-    "fastmcp==2.12.0",
+    "fastmcp==3.1.1",
     "langchain>=0.3.26",
     "scikit-learn>=1.0.0",
     "numpy>=1.24.0",