Bump astral-sh/setup-uv from 5 to 6 in the github_actions group

Bumps the github_actions group with 1 update: [astral-sh/setup-uv](https://github.com/astral-sh/setup-uv).


Updates `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
  dependency-group: github_actions
...

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

Author: dependabot[bot]

.github/workflows/rich-codex.yaml

@@ -16,7 +16,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
-      - uses: astral-sh/setup-uv@v5
+      - uses: astral-sh/setup-uv@v6
       - name: Setup Python
         run: uv python install '3.13'
       - name: Install project

.github/workflows/testing.yaml

@@ -33,7 +33,7 @@ jobs:
     runs-on: ${{ matrix.os }}
     steps:
       - uses: actions/checkout@v4
-      - uses: astral-sh/setup-uv@v5
+      - uses: astral-sh/setup-uv@v6
       - name: Setup Python
         run: uv python install ${{ matrix.python-version }}
       - name: Install project