update master_changes

Author: Firobe

master_changes.md

@@ -84,6 +84,7 @@ users)
 ## VCS
 
 ## Build
+  * Fix Windows build on MSYS2 [#6862 @Firobe]
   * opam no longer depends on `cmdliner` [#6755 @kit-ty-kate - fix #6425]
   * Clean variables before calling make on different projects to avoid clashes [#6769 @kit-ty-kate]
   * Add the upcoming OCaml 5.5 (trunk) support when using dune's dev profile [#6670 @kit-ty-kate]