Add delay before run the 'wait' job

In order to save CI runner resources, this is a proposal for delaying the start of the 'wait' job.

Analyzing the last 100 runs of 'wait' job, we can see that the average duration of the 'wait' job is around 150 seconds and that is rarely under 130 seconds. So I propose here to wait 140 seconds before starting the wait job.

tested here: https://gitlab.com/sylva-projects/sylva-core/-/pipelines/1475117652