gnu: guix: Update development snapshot.

* gnu/packages/package-management.scm (guix-devel): Update to 4420940.
(guix): Set to GUIX-DEVEL.

gnu/packages/package-management.scm

@@ -212,9 +212,9 @@ the Nix package manager.")
   ;;
   ;; Note: use a very short commit id; with a longer one, the limit on
   ;; hash-bang lines would be exceeded while running the tests.
-  (let ((commit "97c8aef15de89799ac01b62dd9b91245c23eefcb"))
+  (let ((commit "4420940f20a2f36f29519f686bca7b85be6be5c9"))
     (package (inherit guix-0.11.0)
-      (version (string-append "0.10.0-1." (string-take commit 4)))
+      (version (string-append "0.11.0-1." (string-take commit 4)))
       (source (origin
                 (method git-fetch)
                 (uri (git-reference
@@ -224,7 +224,7 @@ the Nix package manager.")
                       (commit commit)))
                 (sha256
                  (base32
-                  "0sdxq87mbvig7785gzf52ywmvl3p1q1qgsczmkzrlw988xkma1dr"))
+                  "1c1rqsfc4vrclkk03aj1m8r1lzk9pfa61ax9hhhj5nw23bilsixc"))
                 (file-name (string-append "guix-" version "-checkout"))))
       (arguments
        (substitute-keyword-arguments (package-arguments guix-0.11.0)
@@ -253,7 +253,7 @@ the Nix package manager.")
          ("help2man" ,help2man)
          ,@(package-native-inputs guix-0.11.0))))))
 
-(define-public guix guix-0.11.0)
+(define-public guix guix-devel)
 
 (define (source-file? file stat)
   "Return true if FILE is likely a source file, false if it is a typical