macOS: fix building with old xcode

Makes homebrew happy
Homebrew/homebrew-core#119329

Author: CarterLi

src/detection/wifi/wifi_apple.m

@@ -60,7 +60,7 @@
             case kCWPHYMode11ac:
                 ffStrbufAppendS(&item->conn.phyType, "802.11ac (Wi-Fi 5)");
                 break;
-            case kCWPHYMode11ax:
+            case 6 /*kCWPHYMode11ax*/:
                 ffStrbufAppendS(&item->conn.phyType, "802.11ax (Wi-Fi 6)");
                 break;
             case 7 /*kCWPHYMode11be?*/: