Hide theme and accent color settings on tvOS

These settings don't work well on Apple TV, so exclude the
ThemeSection, AccentColorSection, and the .preferredColorScheme/.tint
modifiers from tvOS builds.

Yattee/Views/Settings/AppearanceSettingsView.swift

@@ -14,7 +14,9 @@ struct AppearanceSettingsView: View {
         Form {
             if let settings = appEnvironment?.settingsManager {
                 // Theme section
+                #if !os(tvOS)
                 ThemeSection(settings: settings)
+                #endif
 
                 // App icon section (iOS only)
                 #if os(iOS)
@@ -22,7 +24,9 @@ struct AppearanceSettingsView: View {
                 #endif
 
                 // Accent color section
+                #if !os(tvOS)
                 AccentColorSection(settings: settings)
+                #endif
 
                 // List style section
                 ListStyleSection(settings: settings)

Yattee/YatteeApp.swift

@@ -60,8 +60,10 @@ struct YatteeApp: App {
         WindowGroup {
             ContentView()
                 .appEnvironment(appEnvironment)
+                #if !os(tvOS)
                 .preferredColorScheme(appEnvironment.settingsManager.theme.colorScheme)
                 .tint(appEnvironment.settingsManager.accentColor.color)
+                #endif
                 #if os(macOS)
                 // Required on the view to prevent new windows on URL open
                 .handlesExternalEvents(preferring: ["*"], allowing: ["*"])