Revert "Manage the CI Python interpreter with uv"

This reverts commit eed5995.

Author: tpvasconcelos

.github/actions/setup-python/action.yml

@@ -13,20 +13,18 @@ inputs:
 runs:
   using: composite
   steps:
-    # Install uv together with a uv-managed Python interpreter, and
-    # create and activate a virtual environment that is used by all
-    # subsequent steps (e.g. the `uv pip install` step below installs
-    # into it). Also enables uv's built-in cache. The cache key takes
-    # the platform, the uv version, and a hash of the files below
-    # into account.
+    - uses: actions/setup-python@v5
+      with:
+        python-version: "${{ inputs.python-version }}"
+
+    # Install uv and enable its built-in cache. The cache key takes the
+    # platform, the uv version, and a hash of the files below into account.
     # See https://docs.astral.sh/uv/guides/integration/github/ for details.
     # NOTE: setup-uv publishes immutable releases only (no
     #       floating major tags), so we pin the full version
-    - name: Install uv and python
+    - name: Install uv
       uses: astral-sh/setup-uv@v9.0.0
       with:
-        python-version: "${{ inputs.python-version }}"
-        activate-environment: true
         enable-cache: true
         cache-suffix: "py${{ inputs.python-version }}"
         cache-dependency-glob: |
@@ -36,4 +34,4 @@ runs:
     - name: Install requirements
       if: ${{ inputs.requirements != '' }}
       shell: bash
-      run: uv pip install --verbose ${{ inputs.requirements }}
+      run: uv pip install --verbose --system ${{ inputs.requirements }}