add shopt -s globstar

[wozhub]

This would enable globstar support on promtool_actions_files parameters like

- name: Check Prometheus alert rules
      uses: peimanja/promtool-github-actions@master
      with:
        promtool_actions_subcommand: 'rules'
        promtool_actions_files: '**/prometheus-rules.yaml'
        promtool_actions_version: '2.14.0'