gnu: python-mutagen: Update to 1.35.1.

* gnu/packages/music.scm (python-mutagen, python2-mutagen): Update to 1.35.1.
[native-inputs]: Add python-pytest.

gnu/packages/music.scm

@@ -1796,14 +1796,16 @@ event-based scripts for scrobbling, notifications, etc.")
 (define-public python-mutagen
   (package
     (name "python-mutagen")
-    (version "1.31")
+    (version "1.35.1")
     (source (origin
               (method url-fetch)
               (uri (pypi-uri "mutagen" version))
               (sha256
                (base32
-                "16fnnhspniac2i7qswxafawsh2x2a803hmc6bn9k1zl5fxq1380a"))))
+                "0klk68c1n3285vvm2xzk8ii7mlqp1dxii04askan0gi1wlpagka9"))))
     (build-system python-build-system)
+    (native-inputs
+     `(("python-pytest" ,python-pytest)))
     (home-page "https://bitbucket.org/lazka/mutagen")
     (synopsis "Read and write audio tags")
     (description "Mutagen is a Python module to handle audio metadata.  It