[Index management] Fix test in index template wizard (#83150)

Author: sebelga

x-pack/plugins/index_management/__jest__/client_integration/index_template_wizard/template_create.test.tsx

@@ -266,9 +266,7 @@ describe('<TemplateCreate />', () => {
       it('should not allow invalid json', async () => {
         const { form, actions } = testBed;
 
-        await act(async () => {
-          actions.completeStepThree('{ invalidJsonString ');
-        });
+        await actions.completeStepThree('{ invalidJsonString ');
 
         expect(form.getErrorsMessages()).toContain('Invalid JSON format.');
       });

x-pack/plugins/index_management/__jest__/client_integration/index_template_wizard/template_form.helpers.ts

@@ -208,7 +208,9 @@ export const formSetup = async (initTestBed: SetupFunc<TestSubjects>) => {
           jsonString: settings,
         }); // Using mocked EuiCodeEditor
       }
+    });
 
+    await act(async () => {
       clickNextButton();
     });