dev-libs/libxls: remove unused patch

Signed-off-by: Michael Mair-Keimberger <mm1ke@gentoo.org>

dev-libs/libxls/files/libxls-1.6.2-gcc13.patch

@@ -1,25 +0,0 @@
-https://github.com/libxls/libxls/pull/118
-
-From f46aea10c50fb08657c15f8f3e813d5434b8b4d5 Mon Sep 17 00:00:00 2001
-From: Elliott Sales de Andrade <quantum.analyst@gmail.com>
-Date: Wed, 18 Jan 2023 05:21:23 -0500
-Subject: [PATCH] Fix header include in C++ mode
-
-This file is included in the toplevel `xls.h` within an `extern "C"`,
-which means including C++ headers in it is completely broken. With GCC
-13, this causes strange errors due to "missing" symbols.
---- a/include/libxls/xlstypes.h
-+++ b/include/libxls/xlstypes.h
-@@ -36,11 +36,7 @@
- #ifndef XLS_TYPES_INC
- #define XLS_TYPES_INC
- 
--#ifdef __cplusplus
--#include <cstdint>
--#else
- #include <stdint.h>
--#endif
- #include <sys/types.h>
- 
- typedef unsigned char		BYTE;
-