test: Fixes act errors in ErrorMessage tests (#21414)

superset-frontend/src/components/ErrorMessage/TimeoutErrorMessage.test.tsx

@@ -23,6 +23,13 @@ import { render, screen } from 'spec/helpers/testing-library';
 import TimeoutErrorMessage from './TimeoutErrorMessage';
 import { ErrorLevel, ErrorSource, ErrorTypeEnum } from './types';
 
+jest.mock(
+  'src/components/Icons/Icon',
+  () =>
+    ({ fileName }: { fileName: string }) =>
+      <span role="img" aria-label={fileName.replace('_', '-')} />,
+);
+
 const mockedProps = {
   error: {
     error_type: ErrorTypeEnum.FRONTEND_TIMEOUT_ERROR,