Revert "Merge branch 'ajwalker/after_script-kamil' into 'master'"

What does this MR do?

Revert !2443 (merged)

Why was this MR needed?

In !2466 (closed) we are facing some problems with cancelation on the Prepare stage of the environment and reporting the wrong error. Today is feature freeze day and we don't have the time to fix it and we don't want to ship 13.5 with this regression

What's the best way to test this MR?

Make sure all after_script tests run successfully. Create a job that has after_script and make sure it runs.