gnu: Remove meson-0.59 workarounds.

Mostly automated with the following command:

$ grep --include='*.scm' '#:meson ,meson-0.59' -rl \
    | xargs sed -z 's/#:meson[^\n]*\s*//' -i

* gnu/packages/freedesktop.scm (malcontent)
(accountsservice): Delete #:meson argument.
* gnu/packages/games.scm (gnome-2048): Likewise.
* gnu/packages/geo.scm (gnome-maps): Likewise.
* gnu/packages/gnome.scm (gnome-photos, gnome-music)
(gnome-initial-setup, gnome-user-share, gnome-characters)
(gnome-disk-utility, gnome-font-viewer, evince, glade3)
(gnome-mines, gnome-sudoku, gnome-settings-daemon, devhelp)
(totem, eog, gvfs, simple-scan, epiphany, gnome-session, gedit)
(network-manager-applet, gnome-control-center, gnome-shell, nautilus)
(gnome-default-applications, gnome-weather, gnome-tweaks, cheese, gthumb)
(gitg, polari, gnome-boxes, gtranslator): Likewise.
* gnu/packages/gtk.scm: (gtkmm-3): Likewise.
* gnu/packages/pdf.scm (zathura): Likewise.
* gnu/packages/photo.scm (entangle): Likewise.
* gnu/packages/video.scm (pitivi): Likewise.
* gnu/packages/virtualization.scm (libvirt-glib): Likewise.

gnu/packages/freedesktop.scm

@@ -353,8 +353,7 @@ tests.")
         (base32 "0vnf0pk516fwwh41v96c29l2i7h1pnwhivlkbf53kkx1q35g7lb3"))))
     (build-system meson-build-system)
     (arguments
-     `(#:meson ,meson-0.59
-       #:glib-or-gtk? #t
+     `(#:glib-or-gtk? #t
        #:phases
        (modify-phases %standard-phases
          ;; AppInfo not available inside build environment.
@@ -1378,8 +1377,7 @@ message bus.")
         (base32 "16wwd633jak9ajyr1f1h047rmd09fhf3kzjz6g5xjsz0lwcj8azz"))))
     (build-system meson-build-system)
     (arguments
-     `(#:meson ,meson-0.59 ;see https://github.com/mesonbuild/meson/issues/6470
-       #:tests? #f ; XXX: tests require DocBook 4.1.2
+     `(#:tests? #f ; XXX: tests require DocBook 4.1.2
        #:configure-flags
        '("--localstatedir=/var"
          "-Dsystemdsystemunitdir=/tmp/empty"