Fix for code scanning alert: Multiplication result converted to larger type

Co-authored-by: Copilot Autofix powered by AI <62310815+github-advanced-security[bot]@users.noreply.github.com>

src/RageSurface.cpp

@@ -137,8 +137,8 @@ RageSurface::RageSurface( const RageSurface &cpy )
 	pixels_owned = true;
 	if( cpy.pixels )
 	{
-		pixels = new uint8_t[ pitch*h ];
-		memcpy( pixels, cpy.pixels, pitch*h );
+		pixels = new uint8_t[ static_cast<size_t>(pitch) * h ];
+		memcpy( pixels, cpy.pixels, static_cast<size_t>(pitch) * h );
 	}
 	else
 		pixels = nullptr;