Remove redundant #available(iOS 13, *) checks

They always return `true` since the deployment version is 13.0, and will
soon become 14.0.

Only one has been left, in `WidgetStyles.swift`, because it will change
again when bumping the deployment target to 14+.

Author: mokagio

WordPress/Classes/ViewRelated/Activity/Filter/FilterChipButton.swift

@@ -94,7 +94,7 @@ class FilterChipButton: UIView {
     override func traitCollectionDidChange(_ previousTraitCollection: UITraitCollection?) {
         super.traitCollectionDidChange(previousTraitCollection)
 
-        if #available(iOS 13, *), traitCollection.hasDifferentColorAppearance(comparedTo: previousTraitCollection) {
+        if traitCollection.hasDifferentColorAppearance(comparedTo: previousTraitCollection) {
             applyColors()
         }
     }

WordPress/Classes/ViewRelated/Blog/Blog + Me/GravatarButtonView.swift

@@ -66,13 +66,7 @@ extension GravatarButtonView {
 extension GravatarButtonView {
 
     private struct StandardBorder {
-        static var color: UIColor {
-            if #available(iOS 13, *) {
-                return .separator
-            }
-
-            return .gray(.shade20)
-        }
+        static var color: UIColor = .separator
 
         static let width = CGFloat(0.5)
     }

WordPress/Classes/ViewRelated/Blog/Blogging Reminders/Time Selector/TimeSelectionView.swift

@@ -8,10 +8,7 @@ class TimeSelectionView: UIView {
     private lazy var timePicker: UIDatePicker = {
         let datePicker = UIDatePicker()
 
-        if #available(iOS 13.4, *) {
-            datePicker.preferredDatePickerStyle = .wheels
-        }
-
+        datePicker.preferredDatePickerStyle = .wheels
         datePicker.datePickerMode = .time
         datePicker.translatesAutoresizingMaskIntoConstraints = false
         datePicker.setDate(selectedTime, animated: false)

WordPress/Classes/ViewRelated/Domains/Domain registration/RegisterDomainSuggestions/DomainSuggestionsTableViewController.swift

@@ -118,10 +118,8 @@ class DomainSuggestionsTableViewController: UITableViewController {
     override func traitCollectionDidChange(_ previousTraitCollection: UITraitCollection?) {
         super.traitCollectionDidChange(previousTraitCollection)
 
-        if #available(iOS 13, *) {
-            if traitCollection.userInterfaceStyle != previousTraitCollection?.userInterfaceStyle {
-                tableView.reloadData()
-            }
+        if traitCollection.userInterfaceStyle != previousTraitCollection?.userInterfaceStyle {
+            tableView.reloadData()
         }
     }
 

WordPress/Classes/ViewRelated/Gutenberg/GutenbergWeb/GutenbergWebNavigationViewController.swift

@@ -32,9 +32,7 @@ class GutenbergWebNavigationController: UINavigationController {
             super.present(viewControllerToPresent, animated: flag, completion: completion)
         }
 
-        guard
-            #available(iOS 13, *),
-            let menuViewControllerClass = NSClassFromString("UIDocumentMenuViewController"), // Silence deprecation warning.
+        guard let menuViewControllerClass = NSClassFromString("UIDocumentMenuViewController"), // Silence deprecation warning.
             viewControllerToPresent.isKind(of: menuViewControllerClass),
             UIDevice.current.userInterfaceIdiom == .phone
         else {

WordPress/Classes/ViewRelated/Gutenberg/Views/GutenGhostView.swift

@@ -95,12 +95,7 @@ class GutenGhostView: UIView {
 }
 
 private extension UIColor {
-    static var ghostToolbarBackground: UIColor {
-        if #available(iOS 13, *) {
-            return UIColor(light: .clear, dark: UIColor.colorFromHex("2e2e2e"))
-        }
-        return .clear
-    }
+    static var ghostToolbarBackground: UIColor = UIColor(light: .clear, dark: UIColor.colorFromHex("2e2e2e"))
 
     static var ghostBlockBackground: UIColor {
         return UIColor(light: .clear, dark: .systemGray5)

WordPress/Classes/ViewRelated/Post/AuthorFilterViewController.swift

@@ -48,11 +48,7 @@ class AuthorFilterViewController: UITableViewController {
         tableView.separatorColor = .clear
         tableView.isScrollEnabled = false
         tableView.showsVerticalScrollIndicator = false
-        if #available(iOS 13, *) {
-            tableView.contentInset = .zero
-        } else {
-            tableView.contentInset = UIEdgeInsets(top: -Metrics.topinset, left: 0, bottom: 0, right: 0)
-        }
+        tableView.contentInset = .zero
     }
 
     required init?(coder aDecoder: NSCoder) {

WordPress/Classes/ViewRelated/Post/PostTagPickerViewController.swift

@@ -145,9 +145,7 @@ class PostTagPickerViewController: UIViewController {
 
     override func traitCollectionDidChange(_ previousTraitCollection: UITraitCollection?) {
         super.traitCollectionDidChange(previousTraitCollection)
-        if #available(iOS 13, *) {
-            textViewContainer.layer.borderColor = UIColor.divider.cgColor
-        }
+        textViewContainer.layer.borderColor = UIColor.divider.cgColor
     }
 
     @objc func doneButtonPressed() {

WordPress/Classes/ViewRelated/Reader/Detail/WebView/ReaderWebView.swift

@@ -159,19 +159,15 @@ class ReaderWebView: WKWebView {
     /// Maps app colors to CSS colors to be applied in the webview
     ///
     private func cssColors() -> String {
-        if #available(iOS 13, *) {
-            return """
-                @media (prefers-color-scheme: dark) {
-                    \(mappedCSSColors(.dark))
-                }
-
-                @media (prefers-color-scheme: light) {
-                    \(mappedCSSColors(.light))
-                }
-            """
-        }
+        return """
+            @media (prefers-color-scheme: dark) {
+                \(mappedCSSColors(.dark))
+            }
 
-        return lightCSSColors()
+            @media (prefers-color-scheme: light) {
+                \(mappedCSSColors(.light))
+            }
+        """
     }
 
     /// If iOS 13, returns light and dark colors

WordPress/Classes/ViewRelated/Reader/Select Interests/ReaderInterestsStyleGuide.swift

@@ -36,13 +36,7 @@ class ReaderInterestsStyleGuide {
     }
 
     // MARK: - Next Button
-    public class var buttonContainerViewBackgroundColor: UIColor {
-        if #available(iOS 13, *) {
-            return .tertiarySystemBackground
-        }
-
-        return .white
-    }
+    public static var buttonContainerViewBackgroundColor: UIColor = .tertiarySystemBackground
 
     public class func applyNextButtonStyle(button: FancyButton) {
         let disabledBackgroundColor: UIColor