Prepare release 2.6.0 (Lightning-AI#21368)

release-prep

Author: justusschock

src/lightning/fabric/CHANGELOG.md

@@ -4,18 +4,7 @@ All notable changes to this project will be documented in this file.
 
 The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/).
 
-
-## [unreleased] - YYYY-MM-DD
-
-### Added
-
--
-
-
-### Removed
-
--
-
+## [2.6.0] - 2025-11-21
 
 ### Changed
 

src/lightning/pytorch/CHANGELOG.md

@@ -6,7 +6,7 @@ The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/).
 
 ---
 
-## [unreleased] - YYYY-MM-DD
+## [2.6.0] - 2025-11-21
 
 ### Added
 

src/version.info

@@ -1 +1 @@
-2.6.0dev0
+2.6.0