Prevent clipboard copying alt value from profile images
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### Proposal
A user may wish to copy the contents of a commit message into a document/Email/IM/etc. from GitLab's user interface. Content can be selected and a `CTRL-C` to copy the content into the clipboard. However, if the commit messages includes a resolved user/avatar link, the copied content will include the `alt` text of the user's profile.
For example, this selection of a [commit message](https://gitlab.com/jdknight/git-commit-formatting/-/commit/671b0c5fb0d198441ccfd48bbcb45f1fc2950419) from GitLab's UI:
{width=628 height=488}
With result in the following content:
```
This is a test.
With another line and sign-off.
Signed-off-by: default avatarJames Knight <git@...>
```
It would be nice to not include `default avatar` in the copied content.
This should be achievable by somehow applying the following style hint for avatars:
```
user-select: none;
```
issue