Apple's list of challenges in China appears to be growing. The country is tightening restrictions on the app store that would eliminate a popular loophole. Advertisement China could soon crack down on a major loophole in its "Great Firewall" that allows its citizens using Apple's App Store to access some otherwise forbidden apps. The tech giant has been meeting with Chinese officials about restrictive new rules that would take away the foreign apps currently offered on the App Store, The Wall Street Journal reported. Social media apps like X, Instagram, Facebook, WhatsApp, and YouTube are at risk of being unavailable…