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/api/v1/repo/repo.go

@@ -983,7 +983,7 @@ func updateRepoUnits(ctx *context.APIContext, opts api.EditRepoOption) error {
 	}
 
 	if len(units)+len(deleteUnitTypes) > 0 {
-		if err := repo_model.UpdateRepositoryUnits(ctx, repo, units, deleteUnitTypes); err != nil {
+		if err := repo_service.UpdateRepositoryUnits(ctx, repo, units, deleteUnitTypes); err != nil {
 			ctx.Error(http.StatusInternalServerError, "UpdateRepositoryUnits", err)
 			return err
 		}