Remove --build-v8-with-gn configure option

This option is now outdated and not used any longer.

configure.py

@@ -36,10 +36,6 @@
 import getmoduleversion
 from gyp_node import run_gyp
 
-# imports in deps/v8/tools/node
-sys.path.insert(0, os.path.join('deps', 'v8', 'tools', 'node'))
-from fetch_deps import FetchDeps
-
 # parse our options
 parser = optparse.OptionParser()
 
@@ -550,12 +546,6 @@
     help='do not use V8 includes from the bundled deps folder. ' +
          '(This mode is not officially supported for regular applications)')
 
-parser.add_option('--build-v8-with-gn',
-    action='store_true',
-    dest='build_v8_with_gn',
-    default=False,
-    help='build V8 using GN instead of gyp')
-
 parser.add_option('--verbose',
     action='store_true',
     dest='verbose',
@@ -1149,14 +1139,6 @@ def configure_v8(o):
     o['variables']['test_isolation_mode'] = 'noop'  # Needed by d8.gyp.
   if options.without_bundled_v8 and options.enable_d8:
     raise Exception('--enable-d8 is incompatible with --without-bundled-v8.')
-  if options.without_bundled_v8 and options.build_v8_with_gn:
-    raise Exception(
-        '--build-v8-with-gn is incompatible with --without-bundled-v8.')
-  if options.build_v8_with_gn:
-    v8_path = os.path.join('deps', 'v8')
-    print('Fetching dependencies to build V8 with GN')
-    options.build_v8_with_gn = FetchDeps(v8_path)
-  o['variables']['build_v8_with_gn'] = b(options.build_v8_with_gn)
 
 
 def configure_openssl(o):