Refactor some tests (#34580)

1. use `test.MockVariableValue` as much as possible
2. avoid `time.Sleep` as much as possible

models/fixtures/hook_task.yml

@@ -18,7 +18,7 @@
   id: 2
   hook_id: 1
   uuid: uuid2
-  is_delivered: false
+  is_delivered: true
 
 -
   id: 3

models/repo/pushmirror_test.go

@@ -39,8 +39,6 @@ func TestPushMirrorsIterate(t *testing.T) {
 		Interval:       0,
 	})
 
-	time.Sleep(1 * time.Millisecond)
-
 	repo_model.PushMirrorsIterate(db.DefaultContext, 1, func(idx int, bean any) error {
 		m, ok := bean.(*repo_model.PushMirror)
 		assert.True(t, ok)

models/user/user_test.go

@@ -513,11 +513,8 @@ func TestIsUserVisibleToViewer(t *testing.T) {
 }
 
 func Test_ValidateUser(t *testing.T) {
-	oldSetting := setting.Service.AllowedUserVisibilityModesSlice
-	defer func() {
-		setting.Service.AllowedUserVisibilityModesSlice = oldSetting
-	}()
-	setting.Service.AllowedUserVisibilityModesSlice = []bool{true, false, true}
+	defer test.MockVariableValue(&setting.Service.AllowedUserVisibilityModesSlice, []bool{true, false, true})()
+
 	kases := map[*user_model.User]bool{
 		{ID: 1, Visibility: structs.VisibleTypePublic}:  true,
 		{ID: 2, Visibility: structs.VisibleTypeLimited}: false,
@@ -586,12 +583,7 @@ func TestDisabledUserFeatures(t *testing.T) {
 	testValues := container.SetOf(setting.UserFeatureDeletion,
 		setting.UserFeatureManageSSHKeys,
 		setting.UserFeatureManageGPGKeys)
-
-	oldSetting := setting.Admin.ExternalUserDisableFeatures
-	defer func() {
-		setting.Admin.ExternalUserDisableFeatures = oldSetting
-	}()
-	setting.Admin.ExternalUserDisableFeatures = testValues
+	defer test.MockVariableValue(&setting.Admin.ExternalUserDisableFeatures, testValues)()
 
 	user := unittest.AssertExistsAndLoadBean(t, &user_model.User{ID: 1})