Fix incorrect authors argument name

[smoogipoo]

The only reference to this argument in the wiki is --packAuthor, but the command is actually --packAuthors.

Proof:

33613   Running dotnet vpk [linux] pack --packTitle="osu!" --packAuthor="ppy Pty Ltd" --packId="osulazer" --packVersion="2024.911.0" --runtime="linux-x64" --outputDir="C:\Users\smoog\Repos\osu-deploy\releases" --mainExe="osu!" --packDir="C:\Users\smoog\Repos\osu-deploy\staging\osu!.AppDir" --channel="linux-x64" ...
34372   [04:49:50 INF] Directive enabled for cross-compiling from Windows (current os) to Linux.

Unrecognized command or argument '--packAuthor=ppy Pty Ltd'.

[smoogipoo]

efbaace 😆

[peppy]

Sorry, didn't see this yet (way too many notifications the last few days).