Upgrading Mac runner images, Xcode and iOS versions

[sirknightj]

Issue #, if available:

• N/A

Description of changes:

• Mac-11, Mac-12 are no longer supported by GitHub actions.
• Use the supported XCode + iOS SDK + iOS simulator combinations mentioned in https://github.com/actions/runner-images/blob/main/images/macos/macos-13-Readme.md, https://github.com/actions/runner-images/blob/main/images/macos/macos-14-Readme.md, and https://github.com/actions/runner-images/blob/main/images/macos/macos-15-Readme.md
• Updated the minimum deployment target from 11 to 12 because:

/Users/runner/work/amazon-kinesis-video-streams-webrtc-sdk-ios/amazon-kinesis-video-streams-webrtc-sdk-ios/Swift/Pods/Pods.xcodeproj: warning: The iOS Simulator deployment target 'IPHONEOS_DEPLOYMENT_TARGET' is set to 11.0, but the range of supported deployment target versions is 12.0 to 17.5.99. (in target 'AWSCognitoIdentityProviderASF' from project 'Pods')
/Users/runner/work/amazon-kinesis-video-streams-webrtc-sdk-ios/amazon-kinesis-video-streams-webrtc-sdk-ios/Swift/Pods/Pods.xcodeproj: warning: The iOS Simulator deployment target 'IPHONEOS_DEPLOYMENT_TARGET' is set to 11.0, but the range of supported deployment target versions is 12.0 to 17.5.99. (in target 'AWSCognitoIdentityProvider-AWSCognitoIdentityProvider' from project 'Pods')
/Users/runner/work/amazon-kinesis-video-streams-webrtc-sdk-ios/amazon-kinesis-video-streams-webrtc-sdk-ios/Swift/Pods/Pods.xcodeproj: warning: The iOS Simulator deployment target 'IPHONEOS_DEPLOYMENT_TARGET' is set to 11.0, but the range of supported deployment target versions is 12.0 to 17.5.99. (in target 'AWSCognitoIdentityProvider' from project 'Pods')
/Users/runner/work/amazon-kinesis-video-streams-webrtc-sdk-ios/amazon-kinesis-video-streams-webrtc-sdk-ios/Swift/Pods/Pods.xcodeproj: warning: The iOS Simulator deployment target 'IPHONEOS_DEPLOYMENT_TARGET' is set to 11.0, but the range of supported deployment target versions is 12.0 to 17.5.99. (in target 'AWSAuthCore-AWSAuthCore' from project 'Pods')
/Users/runner/work/amazon-kinesis-video-streams-webrtc-sdk-ios/amazon-kinesis-video-streams-webrtc-sdk-ios/Swift/Pods/Pods.xcodeproj: warning: The iOS Simulator deployment target 'IPHONEOS_DEPLOYMENT_TARGET' is set to 11.0, but the range of supported deployment target versions is 12.0 to 17.5.99. (in target 'AWSAuthCore' from project 'Pods')
** BUILD FAILED **


The following build commands failed:
	SwiftEmitModule normal arm64 Emitting\ module\ for\ AWSKinesisVideoWebRTCDemoApp (in target 'AWSKinesisVideoWebRTCDemoApp' from project 'AWSKinesisVideoWebRTCDemoApp')
	SwiftCompile normal arm64 Compiling\ VideoViewController.swift,\ SignInViewController.swift,\ Message.swift,\ AppDelegate.swift,\ GeneratedAssetSymbols.swift /Users/runner/work/amazon-kinesis-video-streams-webrtc-sdk-ios/amazon-kinesis-video-streams-webrtc-sdk-ios/Swift/KVSiOSApp/VideoViewController.swift /Users/runner/work/amazon-kinesis-video-streams-webrtc-sdk-ios/amazon-kinesis-video-streams-webrtc-sdk-ios/Swift/KVSiOSApp/SignInViewController.swift /Users/runner/work/amazon-kinesis-video-streams-webrtc-sdk-ios/amazon-kinesis-video-streams-webrtc-sdk-ios/Swift/KVSiOSApp/Message.swift /Users/runner/work/amazon-kinesis-video-streams-webrtc-sdk-ios/amazon-kinesis-video-streams-webrtc-sdk-ios/Swift/KVSiOSApp/AppDelegate.swift /Users/runner/Library/Developer/Xcode/DerivedData/AWSKinesisVideoWebRTCDemoApp-dblaelzsxroobkbpkiaqqlekjgfe/Build/Intermediates.noindex/AWSKinesisVideoWebRTCDemoApp.build/Debug-iphonesimulator/AWSKinesisVideoWebRTCDemoApp.build/DerivedSources/GeneratedAssetSymbols.swift (in target 'AWSKinesisVideoWebRTCDemoApp' from project 'AWSKinesisVideoWebRTCDemoApp')
(2 failures)

• Added ARCHS=x86_64 to the CI because the Apple Silicon runners (Mac 14, 15), default to using arm64 for the simulator. However, Google WebRTC isn't built for arm64-simulators. https://stackoverflow.com/questions/65978359/xcode-error-building-for-ios-simulator-but-linking-in-dylib-built-for-ios-f

/Users/runner/Library/Developer/Xcode/DerivedData/AWSKinesisVideoWebRTCDemoApp-dblaelzsxroobkbpkiaqqlekjgfe/Build/Intermediates.noindex/AWSKinesisVideoWebRTCDemoApp.build/Debug-iphonesimulator/AWSKinesisVideoWebRTCDemoApp.build/Objects-normal/arm64/AWSKinesisVideoWebRTCDemoApp_dependency_info.dat -o /Users/runner/Library/Developer/Xcode/DerivedData/AWSKinesisVideoWebRTCDemoApp-dblaelzsxroobkbpkiaqqlekjgfe/Build/Products/Debug-iphonesimulator/AWSKinesisVideoWebRTCDemoApp.app/AWSKinesisVideoWebRTCDemoApp
ld: warning: ignoring duplicate libraries: '-lsqlite3', '-lz'
ld: warning: search path '/Users/runner/work/amazon-kinesis-video-streams-webrtc-sdk-ios/amazon-kinesis-video-streams-webrtc-sdk-ios/Swift/build/Debug-iphoneos' not found
** BUILD FAILED **
ld: building for 'iOS-simulator', but linking in dylib (/Users/runner/work/amazon-kinesis-video-streams-webrtc-sdk-ios/amazon-kinesis-video-streams-webrtc-sdk-ios/Swift/Pods/GoogleWebRTC/Frameworks/frameworks/WebRTC.framework/WebRTC) built for 'iOS'

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