Remove "(Universal)" from macOS download

[ann0see]

Short description of changes
Since Jamulus has been available for Arm and Intel for a while now on macOS, we don't need to specifically mention "Universal" anymore in my opinion. This doesn't mean we should drop intel support any time soon.

Context: Fixes an issue? Related issues
No

Status of this Pull Request
Ready for review

What is missing until this pull request can be merged?

Nothing
Does this need translation?
YES

Checklist

• I've verified that this Pull Request follows the general code principles
• I waited some time after this Pull Request was opened and all GitHub checks completed without errors.
• I'm sure that this Pull Request goes to the correct branch

[pljones]

Having "(Universal)" was a hint there were not two (or more) separate downloads, I take it? Given we've got the legacy download (intel only), will it still be clear that the unlabelled one is intended for current macOS versions?

(As I have absolutely no knowledge of the mac ecosystem, I could be talking rubbish...)

[ann0see]

The "universal" note was just a hint that the app supports ARM and Intel natively.
For a short time we had one ARM and one Intel build.

I no longer see the "Universal" term in the wild that often.
Therefore I suggest to drop it.