Fix schedule tasks bugs (#28691)

Fix #28157 

This PR fix the possible bugs about actions schedule.

## The Changes

- Move `UpdateRepositoryUnit` and `SetRepoDefaultBranch` from models to
service layer
- Remove schedules plan from database and cancel waiting & running
schedules tasks in this repository when actions unit has been disabled
or global disabled.
- Remove schedules plan from database and cancel waiting & running
schedules tasks in this repository when default branch changed.

routers/web/repo/setting/setting.go

@@ -594,7 +594,7 @@ func SettingsPost(ctx *context.Context) {
 			return
 		}
 
-		if err := repo_model.UpdateRepositoryUnits(ctx, repo, units, deleteUnitTypes); err != nil {
+		if err := repo_service.UpdateRepositoryUnits(ctx, repo, units, deleteUnitTypes); err != nil {
 			ctx.ServerError("UpdateRepositoryUnits", err)
 			return
 		}