Google ping is deprecated (#444)

See: https://developers.google.com/search/blog/2023/06/sitemaps-lastmod-ping

README.md

@@ -204,10 +204,10 @@ SitemapGenerator.verbose = false
 
 ### Pinging Search Engines
 
-Using `rake sitemap:refresh` will notify Google to let them know that a new sitemap
+Using `rake sitemap:refresh` will notify configured search engines to let them know that a new sitemap
 is available.  To generate new sitemaps without notifying search engines, use `rake sitemap:refresh:no_ping`.
 
-If you want to customize the hash of search engines you can access it at:
+By default no search engines are configured. If you want to customize the hash of search engines you can access it at:
 
 ```ruby
 SitemapGenerator::Sitemap.search_engines

lib/sitemap_generator/link_set.rb

@@ -126,9 +126,7 @@ def initialize(options={})
         :include_root => true,
         :include_index => false,
         :filename => :sitemap,
-        :search_engines => {
-          :google         => "http://www.google.com/webmasters/tools/ping?sitemap=%s"
-        },
+        :search_engines => {},
         :create_index => :auto,
         :compress => true,
         :max_sitemap_links => SitemapGenerator::MAX_SITEMAP_LINKS

spec/sitemap_generator/link_set_spec.rb

@@ -130,12 +130,12 @@
   describe 'search_engines' do
     it 'should have search engines by default' do
       expect(ls.search_engines).to be_a(Hash)
-      expect(ls.search_engines.size).to eq(1)
+      expect(ls.search_engines.size).to eq(0)
     end
 
     it 'should support being modified' do
       ls.search_engines[:newengine] = 'abc'
-      expect(ls.search_engines.size).to eq(2)
+      expect(ls.search_engines.size).to eq(1)
     end
 
     it 'should support being set to nil' do
@@ -149,12 +149,6 @@
   end
 
   describe 'ping search engines' do
-    it 'should not fail' do
-      request = stub_request(:get, //)
-      expect { ls.ping_search_engines }.not_to raise_error
-      expect(request).to have_been_requested.at_least_once
-    end
-
     it 'should raise if no host is set' do
       expect { SitemapGenerator::LinkSet.new.ping_search_engines }.to raise_error(SitemapGenerator::SitemapError, 'No value set for host')
     end