Revert "Xcode extension is now generally available (#36523)"

This reverts commit 6c59a5e.

Author: sophietheking

content/copilot/using-github-copilot/copilot-chat/asking-github-copilot-questions-in-your-ide.md

@@ -362,6 +362,8 @@ To share feedback about {% data variables.product.prodname_copilot_chat_short %}
 
 {% xcode %}
 
+{% data reusables.copilot.xcode-chat-public-preview-note %}
+
 ## Prerequisites
 
 To use {% data variables.product.prodname_copilot %} for Xcode, you must install the {% data variables.product.prodname_copilot %} for Xcode extension. See [AUTOTITLE](/copilot/configuring-github-copilot/installing-the-github-copilot-extension-in-your-environment).

data/reusables/copilot/xcode-chat-public-preview-note.md

@@ -0,0 +1 @@
+> [!NOTE] {% data variables.product.prodname_copilot_chat_short %} in Xcode is in {% data variables.release-phases.public_preview %} and subject to change.