gnu: biber: Update to 2.7.

* gnu/packages/tex.scm (biber)[name]: Rename to 'biber'.
(biber-2.5): Remove variable.

gnu/packages/tex.scm

@@ -4058,7 +4058,7 @@ values (strings, macros, or numbers) pasted together.")
 
 (define-public biber
   (package
-    (name "biber-next")
+    (name "biber")
     (version "2.7")
     (source (origin
               (method url-fetch)
@@ -4136,33 +4136,6 @@ values (strings, macros, or numbers) pasted together.")
 other things it comes with full Unicode support.")
     (license license:artistic2.0)))
 
-;; Our version of texlive comes with biblatex 3.4, which is only compatible
-;; with biber 2.5 according to the compatibility matrix in the biber
-;; documentation.
-(define-public biber-2.5
-  (package (inherit biber)
-    (name "biber")
-    (version "2.5")
-    (source (origin
-              (method url-fetch)
-              (uri (string-append "https://github.com/plk/biber/archive/v"
-                                  version ".tar.gz"))
-              (file-name (string-append name "-" version ".tar.gz"))
-              (sha256
-               (base32
-                "163sd343wkrzwnvj2003m2j0kz517jmjr4savw6f8bjxhj8fdrqv"))))
-    (arguments
-     (substitute-keyword-arguments (package-arguments biber)
-       ((#:phases phases)
-        `(modify-phases ,phases
-           (add-before 'check 'delete-failing-test
-             (lambda _
-               (delete-file "t/sort-order.t")
-               #t))))))
-    (inputs
-     `(("perl-date-simple" ,perl-date-simple)
-       ,@(package-inputs biber)))))
-
 (define-public rubber
   (package
     (name "rubber")