Fix github action "Wordlist Updater - Awesome list of secrets in environment variables"

[ItsIgnacioPortal]

This fixes #816

I also renamed this github action job from update_combined_words to update_awesome-environment-variable-names

You can see that now, runs don't fail if there's no changes to merge: https://github.com/ItsIgnacioPortal/SecLists/actions/runs/3163535893