gnu: python-fitsio: Use G-Expressions.

* gnu/packages/astronomy.scm (python-fitsio): Use G-Expressions.

Signed-off-by: Vinicius Monego <monego@posteo.net>

gnu/packages/astronomy.scm

@@ -476,17 +476,18 @@ in FITS files.")
        (modules '((guix build utils)))
        (snippet
         ;; Remove the bundled cfitsio
-        `(begin
+        #~(begin
             (delete-file-recursively "cfitsio3490")
             (substitute* "MANIFEST.in"
               (("recursive-include cfitsio3490.*$\n") ""))))))
     (build-system python-build-system)
     (arguments
-     `(#:phases
-       (modify-phases %standard-phases
+     (list
+      #:phases
+      #~(modify-phases %standard-phases
           (add-after 'unpack 'unbundle-cfitsio
-           (lambda* (#:key inputs #:allow-other-keys)
-             (let* ((cfitsio (assoc-ref inputs "cfitsio"))
+            (lambda _
+              (let* ((cfitsio #$(this-package-input "cfitsio"))
                      (includedir (string-append "\"" cfitsio "/include\""))
                      (libdir (string-append "\"" cfitsio "/lib\"")))
                 ;; Use Guix' cfitsio instead of the bundled one