feat: update UHF Server script to use setup_ffmpeg

[zackwithak13]

✍️ Description

This PR updates the UHF script to install ffmpeg using the shared setup_ffmpeg function, instead of using the debian repo.

🔗 Related Issue

Fixes #

✅ Prerequisites (X in brackets)

• Self-review completed – Code follows project standards.
• Tested thoroughly – Changes work as expected.
• No security risks – No hardcoded secrets, unnecessary privilege escalations, or permission issues.

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🛠️ Type of Change (X in brackets)

• 🐞 Bug fix – Resolves an issue without breaking functionality.
• ✨ New feature – Adds new, non-breaking functionality.
• 💥 Breaking change – Alters existing functionality in a way that may require updates.
• 🆕 New script – A fully functional and tested script or script set.
• 🌍 Website update – Changes to website-related JSON files or metadata.
• 🔧 Refactoring / Code Cleanup – Improves readability or maintainability without changing functionality.
• 📝 Documentation update – Changes to README, AppName.md, CONTRIBUTING.md, or other docs.

[MickLesk]

setup_ffmpeg build from source and take many time. Why for UHF? and why no profile? Really the FULL FFMPEG Codecs?

[zackwithak13]

@MickLesk I wanted to use the latest stable ffmpeg version, not the one available on stable Debian and figured using the supplied util made most sense. full is the only one to include x265, which is a fairly common codec to use

[MickLesk]

https://github.com/community-scripts/ProxmoxVE/blob/main/misc%2Ftools.func#L3843-L3848

[CrazyWolf13]

@MickLesk I think he is right on that.

Isn't x265 more widely used for it to be only in full?

https://github.com/community-scripts/ProxmoxVE/blob/main/misc%2Ftools.func#L3929-L3930