Retry Github actions to avoid false alarm

[ExplorerRay]

PR #647 adds email notification when CI fails on master branch.

However, some referred Github actions temporarily fails will also trigger email sending currently, and this may become spam for the mailing list. (ref) Therefore, we want to check whether CI is really broken instead of just failing temporarily with retry mechanism.

[yungyuc]

Thank you, @ExplorerRay . Do you plan to work on it immediately?

[ExplorerRay]

No, I may work on it after Sciwork conference ends.

[yungyuc]

Sounds like a plan. When you start to work on it, please leave a comment to notify.