read-only link sharing of .md should not allow changing links from text to link-preview mode

[alexanderdd]

To Reproduce
Steps to reproduce the behavior:

1. create a .md file with a link like example
2. share the file externally via link, but with read-only permission
3. access the link from different browser/computer
4. click the three dots to the left of the link, change it from "text" to "preview"
5. go back to logged-in user and refresh: the preview mode of the link was changed

Expected behavior
in read-only mode, nothing in the document should be allowed to change, also not the way links are displayed

Server details:

• Nextcloud version: "31.0.8"

let me know if you need more details