guix: Apply SSA generation patch to maintain determinism

See:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=123351
https://gcc.gnu.org/pipermail/gcc-patches/2026-January/704817.html

contrib/guix/manifest.scm

@@ -123,7 +123,7 @@ desirable for building Bitcoin Core release binaries."
 
 (define (gcc-libgcc-patches gcc)
   (package-with-extra-patches gcc
-    (search-our-patches "gcc-remap-guix-store.patch")))
+    (search-our-patches "gcc-remap-guix-store.patch" "gcc-ssa-generation.patch")))
 
 (define (binutils-mingw-patches binutils)
   (package-with-extra-patches binutils