Currently this string has different amount of placeholders in v8 and v7 because https://codeberg.org/forgejo/forgejo/pulls/3837 was not backported to v7.
### The problem
This string is currently [not translated](https://translate.codeberg.org/translate/forgejo/forgejo/en/?checksum=405b09ee2c2371d4) in every language. For example, when UI is in Slovenian, it would be in English.
But if someone translates it into Slovenian, it will be something like `Posodobljen %s`. Then we merge the Weblate PR, @forgejo-backport-action creates a backport and we forget to check this backport for presence of `repo_updated`. We ship this as a point release of our LTS v7, and then Slovenian users will literally see `Posodobljen %s` in the UI instead of `Posodobljen včeraj`.
By renaming this key in v7 we protect it from these kinds of regressions.
### Test
Go to Explore, look at repo entries, they should contain relative time.
Reviewed-on: https://codeberg.org/forgejo/forgejo/pulls/4117
Reviewed-by: Earl Warren <earl-warren@noreply.codeberg.org>
Reviewed-by: twenty-panda <twenty-panda@noreply.codeberg.org>