Bump astral-sh/setup-uv from 5 to 6 in /.github/workflows/prepare-action

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/prepare-action/action.yml

@@ -20,7 +20,7 @@ runs:
         python-version-file: "./ansible_collections/hifis/toolkit/.python-version"
 
     - name: "Install uv"
-      uses: "astral-sh/setup-uv@v5"
+      uses: "astral-sh/setup-uv@v6"
       with:
         enable-cache: true
         cache-dependency-glob: "./ansible_collections/hifis/toolkit/uv.lock"