fix: run once in shared dependencies (#1655)

* fix: run once in shared dependencies

* feat: add test

hash.go

@@ -4,15 +4,12 @@ import (
 	"fmt"
 
 	"github.com/go-task/task/v3/internal/hash"
+	"github.com/go-task/task/v3/internal/slicesext"
 	"github.com/go-task/task/v3/taskfile/ast"
 )
 
 func (e *Executor) GetHash(t *ast.Task) (string, error) {
-	r := t.Run
-	if r == "" {
-		r = e.Taskfile.Run
-	}
-
+	r := slicesext.FirstNonZero(t.Run, e.Taskfile.Run)
 	var h hash.HashFunc
 	switch r {
 	case "always":