merge bitcoin#24348: Fix Guix build for Windows

contrib/guix/guix-build

@@ -239,7 +239,7 @@ SOURCE_DATE_EPOCH="${SOURCE_DATE_EPOCH:-$(git log --format=%at -1)}"
 time-machine() {
     # shellcheck disable=SC2086
     guix time-machine --url=https://git.savannah.gnu.org/git/guix.git \
-                      --commit=1ef7a03a148cf5f83ab1820444f6bd50d8e732d1 \
+                      --commit=ae03f401381e956c4c41b4cf495cbde964fa43d0 \
                       --cores="$JOBS" \
                       --keep-failed \
                       --fallback \

contrib/guix/manifest.scm

@@ -167,13 +167,17 @@ desirable for building Dash Core release binaries."
 (define (make-gcc-with-pthreads gcc)
   (package-with-extra-configure-variable gcc "--enable-threads" "posix"))
 
+;; Required to support std::filesystem for mingw-w64 target.
+(define (make-gcc-without-newlib gcc)
+  (package-with-extra-configure-variable gcc "--with-newlib" "no"))
+
 (define (make-mingw-pthreads-cross-toolchain target)
   "Create a cross-compilation toolchain package for TARGET"
   (let* ((xbinutils (cross-binutils target))
          (pthreads-xlibc mingw-w64-x86_64-winpthreads)
          (pthreads-xgcc (make-gcc-with-pthreads
                          (cross-gcc target
-                                    #:xgcc (make-ssp-fixed-gcc base-gcc)
+                                    #:xgcc (make-gcc-without-newlib (make-ssp-fixed-gcc base-gcc))
                                     #:xbinutils xbinutils
                                     #:libc pthreads-xlibc))))
     ;; Define a meta-package that propagates the resulting XBINUTILS, XLIBC, and