gnu: groff-minimal: Inherit phases from groff.

* gnu/packages/groff.scm (groff-minimal)[arguments]: Use
'substitute-keyword-arguments' to prevent phases from "groff" overriding the
phases in groff-minimal.

gnu/packages/groff.scm

@@ -22,6 +22,7 @@
 (define-module (gnu packages groff)
   #:use-module (guix licenses)
   #:use-module (guix packages)
+  #:use-module (guix utils)
   #:use-module (guix download)
   #:use-module (guix git-download)
   #:use-module (guix build-system gnu)
@@ -92,7 +93,9 @@ is usually the formatter of \"man\" documentation pages.")
 
        #:configure-flags '("--docdir=/tmp/trash/doc")
 
-       #:phases (modify-phases %standard-phases
+       ,@(substitute-keyword-arguments (package-arguments groff)
+           ((#:phases phases)
+            `(modify-phases ,phases
                (add-after 'install 'remove-non-essential-programs
                  (lambda* (#:key outputs #:allow-other-keys)
                    ;; Keep only the programs that man-db needs at run time,
@@ -115,9 +118,7 @@ is usually the formatter of \"man\" documentation pages.")
                      (for-each delete-file-recursively
                                (find-files out "^dev(dvi|ps|pdf|html|lj4)$"
                                            #:directories? #t))
-                        #t))))
-
-       ,@(package-arguments groff)))))
+                     #t))))))))))
 
 ;; There are no releases, so we take the latest commit.
 (define-public roffit