ci: remove unused init-python action

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

@@ -1,23 +0,0 @@
-# Important: Do not be tempted to cache the .venv dir (Python virtual environment).
-# When the runner environment changes (e.g. Python is upgraded), the venv will need to be
-# re-created. Trying to upgrade a venv can be complex and it's usually more practical re-create it.
-# We don't save much time anyway by caching the venv so it's not worth the added complexity.
-
-name: "Setup Python venv"
-description: "Creates a Python virtual environment (venv)"
-
-runs:
-  using: "composite"
-
-  steps:
-    - name: Setup Python venv
-      run: |
-        if [ "${{ runner.os }}" == "Windows" ]; then
-          python=python
-        else
-          python=python3
-        fi
-
-        echo "Setting up Python venv, bin=$python"
-        $python -m venv .venv
-      shell: bash