Removing the Codisto files from the Shopify theme usually isn't required but they have no impact on websites.  However, if you want to remove this can easily be done:

1) Go to 'Online Store' in Sales Channels

2) Click on 'Themes' and 'Customize'

 

 

 3) Click 'Edit code'

 4) Open 'Snippets'

 5) Delete 'ebay-default.liquid' and confirm

 

 

 6) Open 'Assets'

 7) Delete 'ebay-bootstrap.css' and 'ebay-styles.css' and confirm.