Copy to clipboard recipe do not work in safari 17

[r-vanooyen]

The recipe "copy to clipboard" do not work with the current safari version. I dont know, if that worked in previous versions of safari. The recipe was introduced with #76

Steps to reproduce bug:

open recipe https://cookbook.vaadin.com/copy-to-clipboard in Safari Browser Click on "Copy to clipboard" Button paste clipboard to some textarea -> this should show your old clipboard

You can not see an exception in the safari developer tools console.

expected behaviour paste clipboard to some textarea -> this should show the content of the textbox of that recipe page

[samie]

Looks like this uses execCommand which is deprecated. Should likely switch to https://developer.mozilla.org/en-US/docs/Web/API/Clipboard_API