Adding product variant with no price gives no error

[brunoslalmeida]

Describe the bug
At the Product Variant management page, if you try to add a new variant with no price it gives no error and the button does not work.

To Reproduce
Steps to reproduce the behavior:

1. Go to the Product Variant Management Page (http://localhost:3000/admin/catalog/products/ID/manage-variants)
2. Click new product variant
3. Fill all but price
4. Click save

Expected behavior
Either the button is suppressed or it shows a error message saying that price is required.

Environment (please complete the following information):

• @vendure/core version: 2.2.6
• Nodejs version 20.11.0
• Database (mysql/postgres etc): sqlite