libarchive: Silence API deprecation warnings

CMake uses old libarchive APIs for now.

Utilities/cmlibarchive/libarchive/archive.h

@@ -104,11 +104,8 @@
 #define	__LA_PRINTF(fmtarg, firstvararg)	/* nothing */
 #endif
 
-#if defined(__GNUC__) && __GNUC__ >= 3 && __GNUC_MINOR__ >= 1
-# define __LA_DEPRECATED __attribute__((deprecated))
-#else
-# define __LA_DEPRECATED
-#endif
+/* CMake uses some deprecated APIs to build with old libarchive versions.  */
+#define __LA_DEPRECATED
 
 #ifdef __cplusplus
 extern "C" {