Remove - Clean up unused constants (#20578)

* Remove color extension

* Remove unused font sizes and fonts

firefox-ios/Client/Frontend/UIConstants.swift

@@ -5,14 +5,6 @@
 import UIKit
 import Shared
 
-extension UIColor {
-    // These are colors which we shouldn't use anymore - we'll migrate to use the new theming system
-    struct LegacyDefaults {
-        // This color should exactly match the ios text highlight
-        static let iOSTextHighlightBlue = UIColor(rgb: 0xccdded)
-    }
-}
-
 public struct UIConstants {
     static let DefaultPadding: CGFloat = 10
     static let SnackbarButtonHeight: CGFloat = 57
@@ -23,12 +15,8 @@ public struct UIConstants {
     static let ZoomPageBarHeight: CGFloat = 54
 
     // Static fonts
-    static let DefaultChromeSize: CGFloat = 16
     static let DefaultChromeSmallSize: CGFloat = 11
-    static let PasscodeEntryFontSize: CGFloat = 36
-    static let DefaultChromeFont = UIFont.systemFont(ofSize: DefaultChromeSize, weight: UIFont.Weight.regular)
     static let DefaultChromeSmallFontBold = UIFont.boldSystemFont(ofSize: DefaultChromeSmallSize)
-    static let PasscodeEntryFont = UIFont.systemFont(ofSize: PasscodeEntryFontSize, weight: UIFont.Weight.bold)
 
     /// JPEG compression quality for persisted screenshots. Must be between 0-1.
     static let ScreenshotQuality: Float = 1