Add disk space cleanup step in release workflow

Added a step to free disk space on Ubuntu before setting up Python.

Author: twsl

project/.github/workflows/release.yaml.jinja

@@ -18,6 +18,9 @@ jobs:
         with:
           fetch-depth: 0
 
+      - name: Free Disk Space (Ubuntu)
+        uses: jlumbroso/free-disk-space@main
+
       {% raw %}- name: Set up Python ${{ env.python-version }}
         uses: actions/setup-python@v6
         with: