[QA] chat notification comes before all the pipline are complete

[SwikritiT]

we get a chat notification of nightly builds and they should only come after all the pipelines are complete but that's not the case for this app. The notification pipeline completes before other pipeline and the notification comes in the chat saying the build was successful even if the build failed.

step to reproduce

1. restart the nightly build
2. see the chat notification in builds channel
3. the notification is there even though the build is still running

[saw-jan]

Similar to https://github.com/owncloud/theme-enterprise/issues/132