CBL-7010: Update min versions of iOS (to 15.0), macOS (to 13.0)

Also updated the submodule fleece to its current master branch that includes updated min versions of iOS and macOS.

Author: jianminzhao

CMakeLists.txt

@@ -22,7 +22,7 @@ SQLite3_UnicodeSN - The snowball tokenizer library for SQLite
 This project is built for the following platforms at Couchbase:
 - Windows 10
 - UWP
-- macOS 12.0
+- macOS 13.0
 - CentOS 7 (gcc 7.x+)
 - Android API 22+
 
@@ -40,7 +40,7 @@ Platform logic is largely separated into the cmake/platform_*.cmake files.  Plat
 cmake_minimum_required (VERSION 3.21.0)
 
 # Mac/apple setup -- must appear before the first "project()" line"
-set(CMAKE_OSX_DEPLOYMENT_TARGET "12.0")
+set(CMAKE_OSX_DEPLOYMENT_TARGET "13.0")
 if(NOT DEFINED CMAKE_OSX_SYSROOT)
     # Tells Mac builds to use the current SDK's headers & libs, not what's in the OS.
     set(CMAKE_OSX_SYSROOT macosx)

Xcode/xcconfigs/Project.xcconfig

@@ -24,8 +24,8 @@ CLANG_STATIC_ANALYZER_MODE = shallow
 LITECORE_VERSION_STRING                            = 3.2.2
 LITECORE_BUILD_NUMBER                              = 0
 
-IPHONEOS_DEPLOYMENT_TARGET                         = 12.0
-MACOSX_DEPLOYMENT_TARGET                           = 12.0
+IPHONEOS_DEPLOYMENT_TARGET                         = 15.0
+MACOSX_DEPLOYMENT_TARGET                           = 13.0
 TVOS_DEPLOYMENT_TARGET                             = 12.0
 ONLY_ACTIVE_ARCH                                   = YES
 SKIP_INSTALL                                       = YES