Remove tvOS and watchOS availability checks.

tvOS 9 and watchOS 2 are the minimum version supported by AFNetworking,
so there’s no reason to do an additional check for them (they will be
included by the `*`).

AFNetworking/AFURLSessionManager.m

@@ -149,7 +149,7 @@ typedef void (^AFURLSessionTaskCompletionHandler)(NSURLResponse *response, id re
             [weakTask suspend];
         };
 #if __has_warning("-Wunguarded-availability")
-        if (@available(iOS 9, macOS 10.11, tvOS 9, watchOS 2, *)) {
+        if (@available(iOS 9, macOS 10.11, *)) {
 #else
         if ([progress respondsToSelector:@selector(setResumingHandler:)]) {
 #endif