iOS: Account for when the older SDK is used when building

Since the pre-built versions of Qt at this point are still built against
the iOS 12.x SDKs, then we need to account for this in order to have the
workaround implemented in e00d888daefbfbd5f17e0772421773f8e295087b still
working when deployed to an iOS 13 based device.

Change-Id: I649a453c549ee272de64624d68f9382276fcba64
Reviewed-by: Tor Arne Vestbø <tor.arne.vestbo@qt.io>
(cherry picked from commit 631efee29371246ba1a1d9d007b23ca08b867191)

src/plugins/platforms/ios/quiview.h

@@ -70,3 +70,8 @@ QT_END_NAMESPACE
 @property (nonatomic, readonly) UIEdgeInsets qt_safeAreaInsets;
 @end
 
+#if !QT_IOS_PLATFORM_SDK_EQUAL_OR_ABOVE(130000)
+@interface UITextInteraction : NSObject
+@end
+#endif
+

src/plugins/platforms/ios/quiview.mm

@@ -628,7 +628,6 @@ Q_LOGGING_CATEGORY(lcQpaTablet, "qt.qpa.input.tablet")
 #endif
 }
 
-#if QT_IOS_PLATFORM_SDK_EQUAL_OR_ABOVE(130000)
 - (void)addInteraction:(id<UIInteraction>)interaction
 {
     if (__builtin_available(iOS 13.0, *)) {
@@ -638,7 +637,6 @@ Q_LOGGING_CATEGORY(lcQpaTablet, "qt.qpa.input.tablet")
 
     [super addInteraction:interaction];
 }
-#endif
 
 @end