build(deps): bump the pip-minor-patch group across 1 directory with 4 updates

Bumps the pip-minor-patch group with 4 updates in the /backend directory: [fastapi](https://github.com/fastapi/fastapi), [uvicorn](https://github.com/Kludex/uvicorn), [sqlalchemy](https://github.com/sqlalchemy/sqlalchemy) and [python-dotenv](https://github.com/theskumar/python-dotenv).


Updates `fastapi` from 0.141.1 to 0.142.2
- [Release notes](https://github.com/fastapi/fastapi/releases)
- [Commits](https://github.com/fastapi/fastapi/compare/0.141.1...0.142.2)

Updates `uvicorn` from 0.52.4 to 0.54.0
- [Release notes](https://github.com/Kludex/uvicorn/releases)
- [Changelog](https://github.com/Kludex/uvicorn/blob/main/docs/release-notes.md)
- [Commits](https://github.com/Kludex/uvicorn/compare/0.52.4...0.54.0)

Updates `sqlalchemy` from 2.0.52 to 2.1.3
- [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)

Updates `python-dotenv` from 1.2.3 to 1.2.4
- [Release notes](https://github.com/theskumar/python-dotenv/releases)
- [Changelog](https://github.com/theskumar/python-dotenv/blob/main/CHANGELOG.md)
- [Commits](https://github.com/theskumar/python-dotenv/compare/v1.2.3...v1.2.4)

---
updated-dependencies:
- dependency-name: fastapi
  dependency-version: 0.142.2
  dependency-type: direct:production
  update-type: version-update:semver-minor
  dependency-group: pip-minor-patch
- dependency-name: uvicorn
  dependency-version: 0.54.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
  dependency-group: pip-minor-patch
- dependency-name: sqlalchemy
  dependency-version: 2.1.3
  dependency-type: direct:production
  update-type: version-update:semver-minor
  dependency-group: pip-minor-patch
- dependency-name: python-dotenv
  dependency-version: 1.2.4
  dependency-type: direct:production
  update-type: version-update:semver-patch
  dependency-group: pip-minor-patch
...

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

backend/requirements.txt

@@ -1,9 +1,9 @@
-fastapi==0.141.1
-uvicorn[standard]==0.52.4
-sqlalchemy==2.0.52
+fastapi==0.142.2
+uvicorn[standard]==0.54.0
+sqlalchemy==2.1.3
 asyncpg==0.31.0
 alembic==1.20.0
 pydantic==2.13.5
 pydantic-settings==2.15.0
-python-dotenv==1.2.3
+python-dotenv==1.2.4
 httpx==0.28.1