meta/files/layers.schema.json: drop the layers property

This is a leftover from one of the RFC iterations, where
the property contained available machines, distros and templates.
As all of those were dropped from the final version, there is no
reason to list the layers either anymore.

Normally this would be a backwards incompatible change, but as
the layer setup itself was just merged, I think we can do a quick
fixup :-)

(From OE-Core rev: 64a774de0e154ef81f20853fec903b17d9985a72)

Signed-off-by: Alexander Kanavin <alex@linutronix.de>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

scripts/oe-setup-layers

@@ -18,20 +18,10 @@ import subprocess
 
 def _do_checkout(args, json):
     layers = json['sources']
-    buildconfs = []
-    oecorepath = ""
     for l_name in layers:
         l_data = layers[l_name]
         layerdir = os.path.abspath(os.path.join(args['destdir'], l_data['path']))
 
-        for ll_name in l_data['layers']:
-            if ll_name == 'meta':
-                oecorepath = layerdir
-            ll_data = l_data['layers'][ll_name]
-            if 'buildconfigs' in ll_data:
-                for c in ll_data['buildconfigs']:
-                    buildconfs.append(os.path.join(layerdir, ll_data['subpath'], c))
-
         if 'contains_this_file' in l_data.keys():
             force_arg = 'force_bootstraplayer_checkout'
             if not args[force_arg]: