gnu: velvet: Improve package style.

* gnu/packages/bioinformatics.scm (velvet)[arguments]: Use G-expressions.
[native-inputs]: Remove label.

gnu/packages/bioinformatics.scm

@@ -17066,20 +17066,20 @@ to an artifact/contaminant file.")
                   (delete-file-recursively "third-party")))))
     (build-system gnu-build-system)
     (arguments
-     `(#:make-flags '("OPENMP=t")
+     (list
+      #:make-flags #~(list "OPENMP=t")
       #:test-target "test"
       #:phases
-       (modify-phases %standard-phases
+      #~(modify-phases %standard-phases
           (delete 'configure)
           (add-after 'unpack 'fix-zlib-include
             (lambda _
               (substitute* "src/binarySequences.c"
                 (("../third-party/zlib-1.2.3/zlib.h") "zlib.h"))))
           (replace 'install
-           (lambda* (#:key outputs #:allow-other-keys)
-             (let* ((out (assoc-ref outputs "out"))
-                    (bin (string-append out "/bin"))
-                    (doc (string-append out "/share/doc/velvet")))
+            (lambda _
+              (let ((bin (string-append #$output "/bin"))
+                    (doc (string-append #$output "/share/doc/velvet")))
                 (mkdir-p bin)
                 (mkdir-p doc)
                 (install-file "velveth" bin)
@@ -17089,14 +17089,14 @@ to an artifact/contaminant file.")
     (inputs
      (list openmpi zlib))
     (native-inputs
-     `(("texlive" ,(texlive-updmap.cfg
+     (list (texlive-updmap.cfg
             (list texlive-ec
                   texlive-graphics
                   texlive-grfext
                   texlive-hyperref
                   texlive-infwarerr
                   texlive-kvoptions
-                          texlive-pdftexcmds)))))
+                  texlive-pdftexcmds))))
     (home-page "https://www.ebi.ac.uk/~zerbino/velvet/")
     (synopsis "Nucleic acid sequence assembler for very short reads")
     (description