main/gtk-doc: remove dependency on py3-six

not needed since 2018
https://gitlab.gnome.org/GNOME/gtk-doc/-/blob/ebf57ee7/NEWS#L97

main/gtk-doc/APKBUILD

 # Maintainer: Natanael Copa <ncopa@alpinelinux.org>
 pkgname=gtk-doc
 pkgver=1.33.2
-pkgrel=2
+pkgrel=3
 pkgdesc="Documentation tool for public library API"
 url="https://wiki.gnome.org/DocumentationProject/GtkDoc"
 arch="noarch"
 license="GPL-2.0-or-later AND GFDL-1.1-or-later"
-depends="docbook-xsl python3 py3-six pkgconf glib-dev py3-pygments"
+depends="docbook-xsl python3 pkgconf glib-dev py3-pygments"
 makedepends="rarian-dev gettext autoconf automake libtool"
 checkdepends="bc"
 source="https://download.gnome.org/sources/gtk-doc/${pkgver%.*}/gtk-doc-$pkgver.tar.xz"
@@ -37,4 +37,6 @@ package() {
 	make DESTDIR="$pkgdir" install
 }
 
-sha512sums="f50f68ab6b4bc59f55e84b49c1481f05700171cbf79eca9ba8f3a142a30a4ba88fe096983ebb8d117a9ef8bcea40934674096683d956f5c54cae457d31f651ab  gtk-doc-1.33.2.tar.xz"
+sha512sums="
+f50f68ab6b4bc59f55e84b49c1481f05700171cbf79eca9ba8f3a142a30a4ba88fe096983ebb8d117a9ef8bcea40934674096683d956f5c54cae457d31f651ab  gtk-doc-1.33.2.tar.xz
+"