chore(deps): bump sqlalchemy from 2.0.30 to 2.0.31 in /backend

Bumps [sqlalchemy](https://github.com/sqlalchemy/sqlalchemy) from 2.0.30 to 2.0.31.
- [Release notes](https://github.com/sqlalchemy/sqlalchemy/releases)
- [Changelog](https://github.com/sqlalchemy/sqlalchemy/blob/main/CHANGES.rst)
- [Commits](https://github.com/sqlalchemy/sqlalchemy/commits)

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

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

backend/requirements.txt

@@ -12,7 +12,7 @@ passlib[bcrypt]==1.7.4
 
 requests==2.32.3
 aiohttp==3.9.5
-sqlalchemy==2.0.30
+sqlalchemy==2.0.31
 alembic==1.13.2
 peewee==3.17.6
 peewee-migrate==1.12.2