doc: Requires Meson >=0.52.0 to build documentation

docs/reference/meson.build

@@ -45,6 +45,9 @@ gtkdoc_common_scan_args = [
 ]
 
 if get_option('gtk_doc')
+  if not meson.version().version_compare('>=0.52.0')
+    error('Building documentation requires Meson >= 0.52.0.')
+  endif
   # Check we have the minimum gtk-doc version required. Older versions won't
   # generate correct documentation.
   dependency('gtk-doc', version : '>=1.32')