MNT: remove duplicate and merge-sync entries from Unreleased changelog (#1062)

The Unreleased section listed PR #1059 twice (it is already recorded
under v1.13.0) and a develop/master sync merge entry (#1058), which the
changelog header explicitly excludes.

Co-authored-by: Claude Fable 5 <noreply@anthropic.com>

Author: Gui-FernandesBR

CHANGELOG.md

@@ -32,13 +32,10 @@ Attention: The newest changes should be on top -->
 
 ### Added
 
-- ENH: Updates develop with master [#1058](https://github.com/RocketPy-Team/RocketPy/pull/1058)
 ### Changed
 
 ### Fixed
 
-- BUG: BUG: Environment not Encoding Necessary Parameters for Decode [#1059](https://github.com/RocketPy-Team/RocketPy/pull/1059)
-
 ## [v1.13.0] - 2026-07-04
 
 ### Added