Fix date in changelog (#2373)

Author: hamishmack

changelog.md

@@ -1,11 +1,11 @@
 This file contains a summary of changes to Haskell.nix and `nix-tools`
 that will impact users.
 
-## Jan 29, 2024
+## Jan 29, 2025
 
 Removed GHC <9.6 from CI.
 
-The latest `nixpkgs-unstable` cause problems with
+The latest `nixpkgs-unstable` caused problems with
   * GHC 8.10.7
   * GHC 9.6.6 mingwW64 (ucrt64 works still as does mingwW64
     with newer GHC versions)