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/main.yml

@@ -22,7 +22,7 @@ jobs:
 
     steps:
       - uses: actions/checkout@v4
-      - uses: astral-sh/setup-uv@v5
+      - uses: astral-sh/setup-uv@v6
         with:
           enable-cache: true
       - run: uv run --extra typing mypy
@@ -42,7 +42,7 @@ jobs:
       - uses: actions/checkout@v4
       - uses: r-lib/actions/setup-tinytex@v2
         if: runner.os != 'Windows'
-      - uses: astral-sh/setup-uv@v5
+      - uses: astral-sh/setup-uv@v6
         with:
           enable-cache: true
           python-version: ${{ matrix.python-version }}