gnu: emacs-ansi: Don't use unstable tarball.

* gnu/packages/emacs-xyz.scm (emacs-ansi)[source]: Use GIT-FETCH and
GIT-FILE-NAME.

gnu/packages/emacs-xyz.scm

@@ -7241,13 +7241,13 @@ (define-public emacs-ansi
     (version "0.4.1")
     (source
      (origin
-       (method url-fetch)
-       (uri (string-append "https://github.com/rejeep/ansi.el/archive/v"
-                           version ".tar.gz"))
-       (file-name (string-append name "-" version ".tar.gz"))
+       (method git-fetch)
+       (uri (git-reference
+             (url "https://github.com/rejeep/ansi.el.git")
+             (commit (string-append "v" version))))
+       (file-name (git-file-name name version))
        (sha256
-        (base32
-         "13jj4vbi98j3p17hs99bmy7g21jd5h4v3wpxk4pkvhylm3bfwjw8"))))
+        (base32 "1hbddxarr40ygvaw4pwaivq2l4f0brszw73w1r50lkjlggb7bl3g"))))
     (build-system emacs-build-system)
     (propagated-inputs
      `(("emacs-dash" ,emacs-dash)