iOS App Store: Update the static MoltenVK to 1.4.2, raise the minimum to iOS 15

1.4.0 and older don't apply dynamic blend constants. The stock 1.4.2 build
needs iOS 15. Non-App Store builds keep their targets and dylib.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

CMakeLists.txt

@@ -1548,7 +1548,8 @@ endif()
 # packaging and code signing
 if(IOS AND NOT LIBRETRO)
 	if(IOS_APP_STORE)
-		set(DEPLOYMENT_TARGET 13.0)
+		# The static MoltenVK in ios/MoltenVK needs 15.0. Keep in sync with cmake/Toolchains/ios.cmake.
+		set(DEPLOYMENT_TARGET 15.0)
 	else()
 		set(DEPLOYMENT_TARGET 11.0)
 	endif()

cmake/Toolchains/ios.cmake

@@ -12,7 +12,12 @@
 # PPSSPP platform flags
 set(MOBILE_DEVICE ON)
 set(USING_GLES2 ON)
-set(IPHONEOS_DEPLOYMENT_TARGET 13.0)
+if(IOS_APP_STORE)
+  # The static MoltenVK in ios/MoltenVK needs 15.0.
+  set(IPHONEOS_DEPLOYMENT_TARGET 15.0)
+else()
+  set(IPHONEOS_DEPLOYMENT_TARGET 13.0)
+endif()
 add_definitions(
   -DGL_ETC1_RGB8_OES=0
   -U__STRICT_ANSI__