Add Zhongtai Virtual to airlines.json

[uetcis]

🔗 Your VATSIM ID

1496934

🔗 Linked Issue

n/a

❓ Type of change

• ✈️ Airline Changes
• 🆕 New Airline
• 🧹 Technical change (refactoring, updates and other improvements)

📚 VA Website

https://mzt.app/

📚 Description

Add Zhongtai Virtual, a new member of VATSIM VA Associate program, to the database.

[uetcis]

MZT/ZHONG TAI has already been showing up in vatsim radar but it seems if I don't make it "virtual": true it woudn't be able show the VA name and link even after setting the right remark (as it checks the fpl rmk only when the airline is found in useDataStore().airlines(icao, true), see code linked below), and thus I'm opening a PR here.

https://github.com/VATSIM-Radar/vatsim-radar/blob/63ce6364ee2812fd623bc10eff90e4c5de42ac72/app/composables/index.ts#L255C1-L259C1