POSIX requires libgen.h to be included for the basename function prototype.

See https://gitlab.alpinelinux.org/alpine/aports/-/issues/16103

diff -upr testdisk-7.2.orig/src/hdaccess.c testdisk-7.2/src/hdaccess.c
--- testdisk-7.2.orig/src/hdaccess.c	2024-05-12 11:35:59.137491246 +0200
+++ testdisk-7.2/src/hdaccess.c	2024-05-12 11:36:51.334218946 +0200
@@ -48,6 +48,9 @@
 #ifdef HAVE_STRING_H
 #include <string.h>
 #endif
+#ifdef HAVE_LIBGEN_H
+#include <libgen.h>
+#endif
 #ifdef HAVE_FCNTL_H
 #include <fcntl.h> 	/* open */
 #endif