fix(macOS): Don't include iOS pull-to-refresh control (#1636)

* Update RNCWebView.h

Limit methods relating to pull to refresh to only iOS

* Update RNCWebView.m

Block methods relating to pull to refresh when the target is macOS as macOS does not have the UIRefreshControl

Co-authored-by: Eloy Durán <eloy.de.enige@gmail.com>

apple/RNCWebView.h

 @property (nonatomic, assign) BOOL ignoreSilentHardwareSwitch;
 @property (nonatomic, copy) NSString * _Nullable allowingReadAccessToURL;
 @property (nonatomic, assign) BOOL pullToRefreshEnabled;
+#if !TARGET_OS_OSX
 @property (nonatomic, weak) UIRefreshControl * refreshControl;
+#endif
 
 #if defined(__IPHONE_OS_VERSION_MAX_ALLOWED) && __IPHONE_OS_VERSION_MAX_ALLOWED >= 130000 /* iOS 13 */
 @property (nonatomic, assign) WKContentMode contentMode;
 - (void)goBack;
 - (void)reload;
 - (void)stopLoading;
+#if !TARGET_OS_OSX
 - (void)addPullToRefreshControl;
 - (void)pullToRefresh:(UIRefreshControl *)refreshControl;
+#endif
 
 @end

apple/RNCWebView.m

     [_webView reload];
   }
 }
-
+#if !TARGET_OS_OSX
 - (void)addPullToRefreshControl
 {
     UIRefreshControl *refreshControl = [[UIRefreshControl alloc] init];
     [refreshControl endRefreshing];
 }
 
-#if !TARGET_OS_OSX
+
 - (void)setPullToRefreshEnabled:(BOOL)pullToRefreshEnabled
 {
     _pullToRefreshEnabled = pullToRefreshEnabled;