Remove disallowed pip usage.

Author: ubernostrum

.github/workflows/ci.yml

@@ -77,8 +77,6 @@ jobs:
       - uses: actions/setup-python@v5
         with:
           python-version: "3.12"
-      - uses: hynek/setup-cached-uv@v2
-      - run: python -Im pip install --system --upgrade coverage[toml]
       - uses: actions/download-artifact@v4
         with:
           pattern: coverage-data-*