Fixed deprecation warnings on Mac and iOS

[sauwming]

Increase default minimum iOS version to 11 as XCode 14 doesn't support deployment to releases older than iOS 11 (note that latest XCode is now XCode 15).
https://developer.apple.com/documentation/xcode-release-notes/xcode-14-release-notes
Building for deployment to OS releases older than macOS 10.13, iOS 11, tvOS 11, and watchOS 4 is no longer supported. (92834476)

Also fixed various deprecation warnings on Mac and iOS:

../src/pjmedia-audiodev/coreaudio_dev.m:557:25: warning: 'kAudioObjectPropertyElementMaster' is
 deprecated: first deprecated in macOS 12.0 [-Wdeprecated-declarations]
        addr.mElement = kAudioObjectPropertyElementMaster;
                        ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
                        kAudioObjectPropertyElementMain

../src/pjmedia-videodev/darwin_dev.m:329:21: warning: 'AVCaptureDeviceTypeBuiltInDuoCamera' is
 deprecated: first deprecated in iOS 10.2 - Use AVCaptureDeviceTypeBuiltInDualCamera instead. [-Wdeprecated-declarations]
                  , AVCaptureDeviceTypeBuiltInDuoCamera

../src/pjmedia-videodev/darwin_dev.m:342:41: warning: 'devices' is deprecated: first deprecated in
 iOS 10.0 - Use AVCaptureDeviceDiscoverySession instead. [-Wdeprecated-declarations]
            dev_list = [AVCaptureDevice devices];

../src/pj/activesock.c:155:37: warning: 'kCFStreamNetworkServiceTypeVoIP' is deprecated: first 
deprecated in iOS 9.0 - use PushKit for VoIP control purposes [-Wdeprecated-declarations]
                                    kCFStreamNetworkServiceTypeVoIP)

[sauwming]

More deprecation after Mac OS Sonoma update (Mac OS 14.0):

../src/pjmedia-videodev/darwin_dev.m:326:21: warning: 'AVCaptureDeviceTypeExternalUnknown' is deprecated:
first deprecated in macOS 14.0 [-Wdeprecated-declarations]

../src/pjmedia-videodev/darwin_dev.m:1271:19: warning: 'AVCaptureVideoOrientation' is deprecated:
first deprecated in macOS 14.0 - Use AVCaptureDeviceRotationCoordinator instead [-Wdeprecated-declarations]

../src/pjmedia-videodev/darwin_dev.m:1289:24: warning: 'videoOrientation' is deprecated:
first deprecated in macOS 14.0 - Use -videoRotationAngle instead [-Wdeprecated-declarations]