Revert "mach: switch to uv for managing python venv (#34504)" (#34548)

This reverts commit 4103421ba5.

Signed-off-by: Mukilan Thiyagarajan <mukilan@igalia.com>

.github/workflows/linux-wpt.yml

@@ -52,10 +52,9 @@ jobs:
           path: ${{ inputs.profile }}-binary-linux
       - name: unPackage binary
         run: tar -xzf ${{ inputs.profile }}-binary-linux/target.tar.gz
-      - name: Setup Python
-        uses: ./.github/actions/setup-python
       - name: Bootstrap dependencies
         run: |
+          python3 -m pip install --upgrade pip
           sudo apt update
           sudo apt install -qy --no-install-recommends mesa-vulkan-drivers
           python3 ./mach bootstrap --skip-lints