pythongh-138171: Migrate iOS testbed location and add Apple build script (python#138176)

Adds tooling to generate and test an iOS XCframework, in a way that will also facilitate
adding other XCframework targets for other Apple platforms (tvOS, watchOS, visionOS and
even macOS, potentially).

---------
Co-authored-by: Hugo van Kemenade <[email protected]>

(cherry picked from commit 35c7e52)

Author: freakboy3742

.github/CODEOWNERS

@@ -293,6 +293,9 @@ Lib/concurrent/futures/interpreter.py  @ericsnowcurrently
 **/*Android*                  @mhsmith @freakboy3742
 **/*android*                  @mhsmith @freakboy3742
 
+# Apple
+/Apple                        @freakboy3742
+
 # iOS (but not termios)
 **/iOS*                       @freakboy3742
 **/ios*                       @freakboy3742

.gitignore

@@ -71,15 +71,15 @@ Lib/test/data/*
 /Makefile
 /Makefile.pre
 /iOSTestbed.*
-iOS/Frameworks/
-iOS/Resources/Info.plist
-iOS/testbed/build
-iOS/testbed/Python.xcframework/ios-*/bin
-iOS/testbed/Python.xcframework/ios-*/include
-iOS/testbed/Python.xcframework/ios-*/lib
-iOS/testbed/Python.xcframework/ios-*/Python.framework
-iOS/testbed/iOSTestbed.xcodeproj/project.xcworkspace
-iOS/testbed/iOSTestbed.xcodeproj/xcuserdata
+Apple/iOS/Frameworks/
+Apple/iOS/Resources/Info.plist
+Apple/testbed/build
+Apple/testbed/Python.xcframework/*/bin
+Apple/testbed/Python.xcframework/*/include
+Apple/testbed/Python.xcframework/*/lib
+Apple/testbed/Python.xcframework/*/Python.framework
+Apple/testbed/*Testbed.xcodeproj/project.xcworkspace
+Apple/testbed/*Testbed.xcodeproj/xcuserdata
 Mac/Makefile
 Mac/PythonLauncher/Info.plist
 Mac/PythonLauncher/Makefile