gnu: font-lato: Switch to font-build-system.

* gnu/packages/fonts.scm (font-lato): Switch to font-build-system.
[source]: Use url-fetch/zipbomb.

gnu/packages/fonts.scm

@@ -197,32 +197,12 @@ sans-serif designed for on-screen reading.  It is used by GNOME@tie{}3.")
     (name "font-lato")
     (version "2.010")
     (source (origin
-              (method url-fetch)
+              (method url-fetch/zipbomb)
               (uri (string-append "http://www.latofonts.com/download/Lato2OFL.zip"))
               (sha256
                (base32
                 "1f5540g0ja1nx3ddd3ywn77xc81ssrxpq8n3gyb9sabyq2b4xda2"))))
-    (build-system trivial-build-system)
+    (build-system font-build-system)
-    (arguments
-     `(#:modules ((guix build utils))
-       #:builder (begin
-                   (use-modules (guix build utils)
-                                (srfi srfi-26))
-
-                   (let ((PATH     (string-append (assoc-ref %build-inputs
-                                                             "unzip")
-                                                  "/bin"))
-                         (font-dir (string-append %output
-                                                  "/share/fonts/truetype")))
-                     (setenv "PATH" PATH)
-                     (system* "unzip" (assoc-ref %build-inputs "source"))
-
-                     (mkdir-p font-dir)
-                     (for-each (lambda (ttf)
-                                 (install-file ttf font-dir))
-                               (find-files "." "\\.ttf$"))))))
-
-    (native-inputs `(("unzip" ,unzip)))
     (home-page "http://www.latofonts.com/lato-free-fonts/")
     (synopsis "Lato sans-serif typeface")
     (description