$NetBSD: patch-doc_meson.build,v 1.3 2019/10/27 10:43:43 nia Exp $

Also search for versioned sphinx-build-s.

--- doc/meson.build.orig	2018-12-22 15:33:23.000000000 +0000
+++ doc/meson.build
@@ -1,4 +1,4 @@
-sphinx = find_program('sphinx-build', required: get_option('manpages'))
+sphinx = find_program('sphinx-build-@PYVERSSUFFIX@', 'sphinx-build', required: get_option('manpages'))
 if sphinx.found()
   custom_target('man pages',
     command: [