build(deps): bump astral-sh/setup-uv from 5 to 6 (python#1033)

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] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

.github/workflows/ci.yml

@@ -17,7 +17,7 @@ jobs:
         run: sudo apt-get install gettext
 
       - name: Install uv
-        uses: astral-sh/setup-uv@v5
+        uses: astral-sh/setup-uv@v6
 
       - name: Validate
         run: VERSION=${{ github.event.repository.default_branch }} JOBS=4 MODE=html make all

.github/workflows/deploy-gh-page.yml

@@ -15,7 +15,7 @@ jobs:
         run: sudo apt-get install gettext
 
       - name: Install uv
-        uses: astral-sh/setup-uv@v5
+        uses: astral-sh/setup-uv@v6
 
       - name: Build
         run: JOBS=4 MODE=html make all

.github/workflows/py313-sync-cpython.yml

@@ -31,7 +31,7 @@ jobs:
         run: sudo apt-get install gettext
 
       - name: Install uv
-        uses: astral-sh/setup-uv@v5
+        uses: astral-sh/setup-uv@v6
 
       - name: Sync with CPython
         run: make clone && make merge && make rm_cpython