build-aux: Update for Guile 3.

* build-aux/guix.scm (arguments): Change 2.2 to 3.0.
(inputs): Change guile@2.2 to guile.

build-aux/guix.scm

@@ -69,15 +69,15 @@
                   (json   (assoc-ref inputs "guile-json"))
                   (sqlite (assoc-ref inputs "guile-sqlite3"))
                   (guix   (assoc-ref inputs "guix"))
-                  (mods   (string-append json "/share/guile/site/2.2:"
-                                         sqlite "/share/guile/site/2.2:"
-                                         guix "/share/guile/site/2.2")))
+                  (mods   (string-append json "/share/guile/site/3.0:"
+                                         sqlite "/share/guile/site/3.0:"
+                                         guix "/share/guile/site/3.0")))
              (wrap-program (string-append out "/bin/cuirass")
                `("GUILE_LOAD_PATH" ":" prefix (,mods))
                `("GUILE_LOAD_COMPILED_PATH" ":" prefix (,mods)))))))))
   (inputs
    (map spec+package-list
-        '("guile@2.2"
+        '("guile"
           "guile-fibers"
           "guile-json"
           "guile-sqlite3"