use simpler solution for blob reader (#5105)

Author: ArtemHoruzhenko

redisinsight/ui/src/pages/browser/components/bulk-actions/BulkDelete/BulkDeleteSummaryButton/BulkDeleteSummaryButton.spec.tsx

@@ -2,12 +2,9 @@ import React from 'react'
 import { render, screen } from '@testing-library/react'
 import BulkDeleteSummaryButton from './BulkDeleteSummaryButton'
 
-const readBlobContent = (blob: Blob) =>
-  new Promise((resolve) => {
-    const reader = new FileReader()
-    reader.onload = () => resolve(reader.result)
-    reader.readAsText(blob)
-  })
+const readBlobContent = async (blob: Blob): Promise<string> => {
+  return blob.text()
+}
 
 const defaultRenderProps = {
   pattern: 'test-pattern',