⬆️ Replace astral-sh/setup-uv action with astral-sh/setup-uv v8

Author: renovate[bot]

.github/workflows/upstream-ci.yaml

@@ -114,7 +114,7 @@ jobs:
         with:
           python-version: "3.14"
       - name: ⚡ Set up uv
-        uses: astral-sh/setup-uv@v7
+        uses: astral-sh/setup-uv@v8
         with:
           version: "0.11.7"
       - name: 🧰 Install test dependencies