Bump astral-sh/setup-uv from 6 to 7

Bumps [astral-sh/setup-uv](https://github.com/astral-sh/setup-uv) from 6 to 7.
- [Release notes](https://github.com/astral-sh/setup-uv/releases)
- [Commits](astral-sh/setup-uv@v6...v7)

---
updated-dependencies:
- dependency-name: astral-sh/setup-uv
  dependency-version: '7'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

Author: dependabot[bot]

.github/workflows/ci.yml

@@ -24,7 +24,7 @@ jobs:
           python-version: ${{ matrix.python-version }}
 
       - name: Set up uv
-        uses: astral-sh/setup-uv@v6
+        uses: astral-sh/setup-uv@v7
 
       - name: Run Django system checks
         run: uv run --no-project --with-requirements requirements-dev.txt python manage.py check