Fixes #140. Seems Apple has bumped the minimum required target to 13.1 in newer versions of Xcode for Mac Catalyst.

Author: Alexander Widerberg

ios.toolchain.cmake

@@ -245,14 +245,14 @@ if(NOT DEFINED DEPLOYMENT_TARGET)
     set(DEPLOYMENT_TARGET "11.0")
   elseif(PLATFORM STREQUAL "MAC_CATALYST" OR PLATFORM STREQUAL "MAC_CATALYST_ARM64")
     # Unless specified, SDK version 13.0 is used by default as minimum target version (mac catalyst minimum requirement).
-    set(DEPLOYMENT_TARGET "13.0")
+    set(DEPLOYMENT_TARGET "13.1")
   else()
     # Unless specified, SDK version 11.0 is used by default as minimum target version (iOS, tvOS).
     set(DEPLOYMENT_TARGET "11.0")
   endif()
   message(STATUS "[DEFAULTS] Using the default min-version since DEPLOYMENT_TARGET not provided!")
-elseif(DEFINED DEPLOYMENT_TARGET AND PLATFORM MATCHES "^MAC_CATALYST" AND ${DEPLOYMENT_TARGET} VERSION_LESS "13.0")
-  message(FATAL_ERROR "Mac Catalyst builds requires a minimum deployment target of 13.0!")
+elseif(DEFINED DEPLOYMENT_TARGET AND PLATFORM MATCHES "^MAC_CATALYST" AND ${DEPLOYMENT_TARGET} VERSION_LESS "13.1")
+  message(FATAL_ERROR "Mac Catalyst builds requires a minimum deployment target of 13.1!")
 endif()
 
 # Store the DEPLOYMENT_TARGET in the cache