To remove unwanted pages from Google, add a noindex tag to the page header or...

https://wool-wiki.win/index.php/My_Site_Has_Both_Trailing_Slash_and_No-Trailing_Slash_URLs_Indexed:_How_Do_I_Clean_It_Up%3F

To remove unwanted pages from Google, add a noindex tag to the page header or return a 404/410 status code. These methods tell search engines to drop the content from their index permanently