fix: stray brace — the sky cap class landed outside the anonymous namespace

My edit anchored on the FACTORIES banner, which sits AFTER the anonymous namespace's
closing brace. So FSkyCapHeightSource was inserted at file scope and the `}` I added
with it closed nothing — C2059 at the following `}`.

Removed the early closer instead of the late one, so the class keeps internal
linkage alongside the other five rather than leaking into the TU's global scope.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

Source/VoxelForge/Private/VoxelHeightOpStack.cpp

@@ -275,7 +275,6 @@ namespace
     private:
         FSurfaceGenerationParams P;
     };
-}
 
     //=========================================================================
     // SOURCE — LE CIEL / SKY CAP  (c'est une ALTITUDE, donc c'est un op de hauteur)
@@ -352,6 +351,7 @@ namespace
     };
 }
 
+
 //=============================================================================
 // FABRIQUES / FACTORIES
 //=============================================================================