Referring to the Copy feature implemented by https://github.com/sindresorhus/refined-github/pull/771
Has Github removed / modified their native zeroclipboard feature?
Try using the copy button in any of the test files in that PR. No text is copied. Example test file, gist file, copy file path
Apparently they changed the implementation, we can probably still use it.

I figured out how this new clipboard-copy element works: either it has a value attribute or a for attribute pointing to an element's id, just like <label for="">
This means that we need to create an id on the spot and refer to it. A simple counter would work:
let button = 0;
...
contentToBoCopied.id = contentToBoCopied.id || `rgh-content-${button++}`;
<clipboard-copy for={contentToBoCopied.id}>
However it looks like they haven't added the feedback tooltips yet.
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Apparently they changed the implementation, we can probably still use it.