Code Quality: Remove beta version of FluentHub

[Lamparter]

📄 Description

Remove the beta assets and references of FluentHub Beta (unused) We could actually implement beta versions when we add automatic releases to MPN/MSStorefront/GitHubReleases in #486 but I'm not sure. @0x5bfa what do you think?

This PR is based on #224

⚡ API Changes

Removes FluentHub Beta (not on MPN/MSStorefront anyway) as unnecessary and semantic releasing with Betas is difficult.

👥 Usage scenarios

No usage scenario provided

🔙 Backward Compatibility

FluentHub beta version never released so there are no compatibility conflicts.

🤔 Difficulty

Low

[Lamparter]

We could also remove the name 'Dev' from FluentHub Dev The icon already tells you. The only problem with this is that build assets may become confusing. I'm not totally sure.

[Lamparter]

@0x5bfa what are your thoughts?

[Lamparter]

@0x5bfa you were already talking about this way back in #224 (2022!)

[0x5bfa]

Loooool 😆