Enable MacOS build in ORT Objc Pod (#18786)

### Description
<!-- Describe your changes. -->

Add macos build for objc pod. 


### Motivation and Context
<!-- - Why is this change required? What problem does it solve?
- If it fixes an open issue, please link to the issue here. -->

Follow up pr for #18550

---------

Co-authored-by: rachguo <rachguo@rachguos-Mini.attlocal.net>

tools/ci_build/github/apple/objectivec/assemble_objc_pod_package.py

@@ -154,6 +154,7 @@ def assemble_objc_pod_package(
         "DESCRIPTION": pod_config["description"],
         "INCLUDE_DIR_LIST": path_patterns_as_variable_value(include_dirs),
         "IOS_DEPLOYMENT_TARGET": framework_info["iphonesimulator"]["APPLE_DEPLOYMENT_TARGET"],
+        "MACOSX_DEPLOYMENT_TARGET": framework_info.get("macosx", {}).get("APPLE_DEPLOYMENT_TARGET", ""),
         "LICENSE_FILE": license_file,
         "NAME": pod_name,
         "PUBLIC_HEADER_FILE_LIST": path_patterns_as_variable_value(pod_files["public_header_files"]),

tools/ci_build/github/apple/objectivec/objc.podspec.template

@@ -8,6 +8,12 @@ Pod::Spec.new do |s|
   s.author           = { "ONNX Runtime" => "onnxruntime@microsoft.com" }
   s.source           = { :http => "file:///http_source_placeholder" }
   s.ios.deployment_target = "@IOS_DEPLOYMENT_TARGET@"
+
+  macosx_deployment_target =  "@MACOSX_DEPLOYMENT_TARGET@"
+  if macosx_deployment_target != ""
+    s.osx.deployment_target = macosx_deployment_target
+  end
+
   s.preserve_paths = [ "@LICENSE_FILE@" ]
   s.default_subspec = "Core"
   s.static_framework = true

tools/ci_build/github/azure-pipelines/templates/stages/mac-ios-packaging-build-stage.yml

@@ -38,7 +38,7 @@ stages:
         cPodName: onnxruntime-training-c
         objcPodName: onnxruntime-training-objc
 
-    timeoutInMinutes: 180
+    timeoutInMinutes: 210
 
     steps:
     - script: |