deps: bump firebase-admin from 6.9.0 to 7.1.0

Bumps [firebase-admin](https://github.com/firebase/firebase-admin-python) from 6.9.0 to 7.1.0.
- [Release notes](https://github.com/firebase/firebase-admin-python/releases)
- [Commits](firebase/firebase-admin-python@v6.9.0...v7.1.0)

---
updated-dependencies:
- dependency-name: firebase-admin
  dependency-version: 7.1.0
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

Author: dependabot[bot]

backend/requirements.txt

@@ -7,7 +7,7 @@ pydantic==2.11.7
 pydantic-settings==2.1.0
 pymongo==4.13.1
 motor==3.7.1
-firebase-admin==6.9.0
+firebase-admin==7.1.0
 python-dotenv==1.0.0
 bcrypt==4.0.1
 email-validator==2.2.0

requirements.txt

@@ -7,7 +7,7 @@ pydantic==2.11.7
 pydantic-settings==2.1.0
 pymongo==4.13.1
 motor==3.7.1
-firebase-admin==6.9.0
+firebase-admin==7.1.0
 python-dotenv==1.0.0
 bcrypt==4.0.1
 email-validator==2.2.0