Partial revert "gnu: make-bootstrap: Update gcc-static to gcc-14, for the 64bit Hurd."

This partially reverts commit ec8a5ec15f.

This part accidentally triggered a world rebuild for non-x86 architectures.

Change-Id: Id2f9bcbcda8dc86ea407e9a7857a854dc1a742b5

gnu/packages/make-bootstrap.scm

@@ -538,7 +538,8 @@ for `sh' in $PATH, and without nscd, and with static NSS modules."
                 (substitute* (cons "gcc/config/rs6000/sysv4.h"
                                    (find-files "gcc/config"
                                                "^gnu-user.*\\.h$"))
-                  ((" -lgcc_s}}") "}}"))))))))
+                  ((" -lgcc_s}}") "}}"))
+                #$@(if (target-hurd64?) '() '(#t))))))))
      (inputs
       `(("zlib:static" ,zlib "static")
         ("isl:static" ,isl "static")