Bump firebase-admin from 6.5.0 to 6.6.0

Bumps [firebase-admin](https://github.com/firebase/firebase-admin-python) from 6.5.0 to 6.6.0.
- [Release notes](https://github.com/firebase/firebase-admin-python/releases)
- [Commits](firebase/firebase-admin-python@v6.5.0...v6.6.0)

---
updated-dependencies:
- dependency-name: firebase-admin
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

Diff for: Pipfile

@@ -12,7 +12,7 @@ coverage = "*"
 requests-mock = "*"
 Flask = ">=3"
 werkzeug = ">=3"
-firebase-admin = "6.5.0"
+firebase-admin = "6.6.0"
 mock-firestore = "*"
 pytest-mock = "*"
 pytest = "*"