Bump astral-sh/setup-uv from 5 to 6

Bumps [astral-sh/setup-uv](https://github.com/astral-sh/setup-uv) from 5 to 6.
- [Release notes](https://github.com/astral-sh/setup-uv/releases)
- [Commits](astral-sh/setup-uv@v5...v6)

---
updated-dependencies:
- dependency-name: astral-sh/setup-uv
  dependency-version: '6'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

Author: dependabot[bot]

.github/workflows/ci.yml

@@ -28,7 +28,7 @@ jobs:
           path: metabrainz.docker
 
       - name: Install uv
-        uses: astral-sh/setup-uv@v5
+        uses: astral-sh/setup-uv@v6
         with:
           version: "0.6.4"
 
@@ -82,7 +82,7 @@ jobs:
           echo "REQS_HASH=$(sha256sum requirements.txt | awk '{ print $1 }')" >> "$GITHUB_ENV"
 
       - name: Install uv and set Python version
-        uses: astral-sh/setup-uv@v5
+        uses: astral-sh/setup-uv@v6
         with:
           version: "0.6.4"
           python-version: ${{ matrix.python }}