Configure scheduled pipeline to run only once

Currently there is no option to run a pipeline only once at a future date/time via the scheduler. You have to set a schedule and remember to delete it after the pipeline has been triggered. This could be useful if you want to merge a pull request ahead of time but deploy at later date/time only once. Example: After hours deployment.

Adding a checkbox with "Run Once" option on the scheduler menu could be a good way to implement this.