macOS: Fix for libusb_get_port_numbers on macOS 26+

macOS 26 has changed port number property name:
```
% diff -u
/Library/Developer/CommandLineTools/SDKs/MacOSX15.sdk/System/Library/
Frameworks/IOKit.framework/Headers/usb/IOUSBHostFamilyDefinitions.h
/Library/Developer/CommandLineTools/SDKs/MacOSX26.sdk/System/Library/
Frameworks/IOKit.framework/Headers/usb/IOUSBHostFamilyDefinitions.h
...
-#define kUSBHostPortPropertyPortNumber                "port"
+#define kUSBHostPortPropertyPortNumber                "usb-port-number"
...
```
Unfortunately, we cannot just use constant `kUSBHostPortPropertyPortNumber`
in libusb code because it would mean that the same binary that works on
macOS 15 will not work on macOS 26.

Solution is to use appropriate string for port number property depending
on running OS version.

Closes libusb#1700

References libusb#1661

Author: mvp

libusb/os/darwin_usb.c

@@ -1309,7 +1309,15 @@ static bool get_device_port (io_service_t service, UInt8 *port) {
 
   kresult = IORegistryEntryGetParentEntry (service, kIOServicePlane, &parent);
   if (kIOReturnSuccess == kresult) {
-    ret = get_ioregistry_value_data (parent, CFSTR("port"), 1, port);
+    /*
+       macOS 10 to 15 always had port number property as "port".
+       macOS 26 has changed it to "usb-port-number".
+       For the same binaries to run correctly on both macOS 15 and macOS 26+,
+       we have to detect os version at runtime and use correct port name property.
+     */
+    uint32_t os_version = get_running_version();
+    CFStringRef cfstrPort = os_version < 260000 ? CFSTR("port") : CFSTR("usb-port-number");
+    ret = get_ioregistry_value_data (parent, cfstrPort, 1, port);
     IOObjectRelease (parent);
   }
 

libusb/version_nano.h

@@ -1 +1 @@
-#define LIBUSB_NANO 11984
+#define LIBUSB_NANO 11986