* disabled the button itself, but added the tooltip to the form, because it didn't work for the button and likely has something to do with JS
* added an integration test to verify the new logic
## Preview
|Signed in|Guest|
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|![](/attachments/b1441565-6aec-4a72-a28f-6383914c8918)|![](/attachments/839cc58e-18cf-4a5d-a9d7-f0e3e2556c98)|
Reviewed-on: https://codeberg.org/forgejo/forgejo/pulls/4095
Reviewed-by: Mai-Lapyst <mai-lapyst@noreply.codeberg.org>