Fix linter issues for golangci-lint 1.54.2

Signed-off-by: Kohei Tokunaga <ktokunaga.mail@gmail.com>

metadata/containers_test.go

@@ -619,6 +619,7 @@ func TestContainersCreateUpdateDelete(t *testing.T) {
 			},
 		},
 	} {
+		testcase := testcase
 		t.Run(testcase.name, func(t *testing.T) {
 			testcase.original.ID = testcase.name
 			if testcase.input.ID == "" {

metadata/images_test.go

@@ -479,6 +479,7 @@ func TestImagesCreateUpdateDelete(t *testing.T) {
 			cause: errdefs.ErrNotFound,
 		},
 	} {
+		testcase := testcase
 		t.Run(testcase.name, func(t *testing.T) {
 			testcase.original.Name = testcase.name
 			if testcase.input.Name == "" {