JavaScript Actions support defining pre, pre-if, post and post-if steps, which allow executing steps at the beginning or the end of a job, regardless of intermediate steps failing. Unfortunately, those are not available for any other Action type.

Action with-post-step is a generic JS Action to execute a main command and to set a command as a post step. It allows using the post feature with scripts written in bash, python or any other interpreted language available on the environment. See: actions/runner#1478.