Async independent job

Problem to solve

Sometimes it may be necessary to complete a job without affecting the result of the current pipeline.

The simplest example is coverage tests.
Now we have to wait for the execution of the coverage tests, although they are performed for a long time, and we only need to perform the usual tests.

Further details

It would be better if we can run them in parallel with the normal execution of tests, and not wait for them to run.

Proposal

For example, if tasks marked allow_failure: true (or another flag) executed asynchronously, and stage didn't wait when its done.