fix: ensure this action also runs with latest Ubuntu 24.04 runner (#53)

action.yml

@@ -56,7 +56,7 @@ runs:
       if [ -n "${{ inputs.plugins }}" ]; then
         plugins="${{ inputs.plugins }}"
       fi
-      pip install flake8${flake8_version} ${plugins}
+      PIP_BREAK_SYSTEM_PACKAGES=1 pip install flake8${flake8_version} ${plugins}
     shell: bash
   - run: ${{ github.action_path }}/action/entrypoint.sh
     shell: bash