self: Build with Guile 3.0.3.

* gnu/packages/guile.scm (guile-3.0/libgc-7): Inherit from GUILE-3.0.3.

gnu/packages/guile.scm

@@ -330,7 +330,7 @@ (define-public guile-3.0/libgc-7
   ;; https://debbugs.gnu.org/cgi/bugreport.cgi?bug=40525
   (hidden-package
    (package
-     (inherit guile-3.0)
+     (inherit guile-3.0.3)
      (propagated-inputs
       `(("bdw-gc" ,libgc-7)
         ,@(srfi-1:alist-delete "bdw-gc" (package-propagated-inputs guile-3.0)))))))