build: sort: explicitly tag libcrypto dependency

This adds an ELF note as per the UAPI Group's .note.dlopen spec:

  $ readelf -p .note.dlopen src/sort
  String dump of section '.note.dlopen':
    [     4]  y
    [     a]  |@FDO
    [    10]  [{"feature":"random-sort",
                "description":"Support for random sorting",
                "priority":"required",
                "soname":["libcrypto.so.3"]}]

* bootstrap.conf: Add sd-dlopen.
* src/sort.c (DLOPEN_LIBCRYPTO && HAVE_OPENSSL_MD5): Add an ELF note
with SD_ELF_NOTE_DLOPEN() so that packagers can determine the libcrypto
dependency, needed when --random-sort is specified.
* NEWS: Mention the Build-related change.

NEWS

@@ -176,6 +176,9 @@ GNU coreutils NEWS                                    -*- outline -*-
   The configure option '--enable-systemd' is renamed to '--with-systemd'.
   The option '--enable-systemd' was a misnomer and is now deprecated.
 
+  The 'sort' binary now uses the UAPI Group's .note.dlopen ELF note
+  to indicate its dependency on libcrypto.
+
 
 * Noteworthy changes in release 9.11 (2026-04-20) [stable]
 

bootstrap.conf

@@ -262,6 +262,7 @@ gnulib_modules="
   save-cwd
   savedir
   savewd
+  sd-dlopen
   select
   selinux-at
   setenv

src/sort.c

@@ -2370,6 +2370,14 @@ getmonth (char const *month, char **ea)
 # endif
 # include <dlfcn.h>
 
+/* Require distributions make OpenSSL available for hardware
+   optimized implementations of MD-5.  */
+# include "sd-dlopen.h"
+SD_ELF_NOTE_DLOPEN ("random-sort",
+                    "Support for random sorting",
+                    SD_ELF_NOTE_DLOPEN_PRIORITY_REQUIRED,
+                    LIBCRYPTO_SONAME);
+
 /* Diagnose a dynamic linking failure.  */
 static void
 link_failure (void)