chore(deps): update astral-sh/setup-uv action to v6

Author: renovate[bot]

.github/workflows/zizmor.yaml

@@ -24,7 +24,7 @@ jobs:
         persist-credentials: false
 
     - name: Install the latest version of uv
-      uses: astral-sh/setup-uv@v5
+      uses: astral-sh/setup-uv@v6
 
     - name: Run zizmor
       run: uvx zizmor .