Docs update re cocoapods future.

DEVELOPMENT.md

@@ -2,14 +2,10 @@
 
 ## Development
 
-You can use CocoaPods or Swift Package Manager.
-
 **Reminder:** Please see the
 [CONTRIBUTING.md](https://github.com/google/gtm-session-fetcher/blob/main/CONTRIBUTING.md)
 file for how to contribute to this project.
 
-## Swift Package Manager
-
 *  `open Package.swift` or double click `Package.swift` in Finder.
 *  Xcode will open the project
    *  The _GTMSessionFetcher-Package_ scheme seems generally the simplest to

USING.md

@@ -16,6 +16,10 @@ The Google Toolbox for Mac Session Fetcher is a set of classes to simplify HTTP
 
 ### Integration via CocoaPods
 
+NOTE: CocoaPods is spinning down in 2026,
+[Announcement](https://blog.cocoapods.org/CocoaPods-Specs-Repo/), so it is in
+your interest to move to Swift Package Manager (SwiftPM) before then.
+
 If you are building from CocoaPods, just use the pod provided: `GTMSessionFetcher`.
 
 The `Core` subspec includes the minimum parts of the library. There is also a `Full` subspec that includes some the multipart MIME uploads and downloads and [resumable-uploads](https://developers.google.com/gdata/docs/resumable_upload). The `LogView` subspec provides an iOS view that can easily be added to applications to allow viewing of the [logging](#http-logging) this library supports.