Send notifications if pipeline schedule failed to create a pipeline
Problem
The feature "Pipeline Schedule" cannot continue creating a pipeline with some case, for example,
- Pipeline owner is no longer a part of project members
- Target branch was set to be protected and the pipeline owner doesn't have an permission to create a pipeline on the protected branch.
- etc
We should notify users that "Why/When" pipeline schedule failed to create a pipeline and guide them a recovery action.
Proposal
- Send a mail to a user (maybe project owner or schedule owner) when pipeline schedule failed to create a pipeline
- Indicate why/when failed, and show a guide how to recover the situation