Update astral-sh/setup-uv action to v6

Author: renovate[bot]

.github/workflows/python-app.yml

@@ -29,7 +29,7 @@ jobs:
     steps:
     - uses: actions/checkout@v4
     - name: Install uv
-      uses: astral-sh/setup-uv@v5
+      uses: astral-sh/setup-uv@v6
       with:
         version: 'latest'
     - run: uv sync