To remove “Showing the single result” in WooCommerce Shop/Category Page, just follow these steps:

Step 1. Install and Activate Code Snippets Plugin
Step 2. Add New Snippet
Step 3. Paste these code (Line 01)
If you use Storefront, use the above code (Lines 04 – 09)
Step 4. Save Changes and Activate
Snippet: Businessbloomer.com