Bump jekyll-sitemap from 1.3.1 to 1.4.0 (#11286)

Bumps [jekyll-sitemap](https://github.com/jekyll/jekyll-sitemap) from 1.3.1 to 1.4.0.
- [Release notes](https://github.com/jekyll/jekyll-sitemap/releases)
- [Changelog](https://github.com/jekyll/jekyll-sitemap/blob/master/History.markdown)
- [Commits](https://github.com/jekyll/jekyll-sitemap/compare/v1.3.1...v1.4.0)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

Co-authored-by: null <27856297+dependabot-preview[bot]@users.noreply.github.com>

Gemfile

@@ -13,7 +13,7 @@ end
 group :jekyll_plugins do
   gem 'jekyll-paginate', '1.1.0'
   gem 'jekyll-redirect-from', '0.15.0'
-  gem 'jekyll-sitemap', '1.3.1'
+  gem 'jekyll-sitemap', '1.4.0'
   gem 'jekyll-time-to-read', '0.1.2'
   gem 'jekyll-commonmark', '1.3.1'
 end

Gemfile.lock

@@ -25,8 +25,8 @@ GEM
       http_parser.rb (~> 0.6.0)
     eventmachine (1.2.7)
     eventmachine (1.2.7-x64-mingw32)
-    ffi (1.11.1)
-    ffi (1.11.1-x64-mingw32)
+    ffi (1.11.2)
+    ffi (1.11.2-x64-mingw32)
     forwardable-extended (2.6.0)
     http_parser.rb (0.6.0)
     i18n (1.7.0)
@@ -54,7 +54,7 @@ GEM
       jekyll (>= 3.3, < 5.0)
     jekyll-sass-converter (2.0.1)
       sassc (> 2.0.1, < 3.0)
-    jekyll-sitemap (1.3.1)
+    jekyll-sitemap (1.4.0)
       jekyll (>= 3.7, < 5.0)
     jekyll-time-to-read (0.1.2)
       jekyll
@@ -85,7 +85,7 @@ GEM
     rb-fsevent (0.10.3)
     rb-inotify (0.10.0)
       ffi (~> 1.0)
-    rouge (3.12.0)
+    rouge (3.13.0)
     ruby-enum (0.7.2)
       i18n
     safe_yaml (1.0.5)
@@ -121,7 +121,7 @@ DEPENDENCIES
   jekyll-commonmark (= 1.3.1)
   jekyll-paginate (= 1.1.0)
   jekyll-redirect-from (= 0.15.0)
-  jekyll-sitemap (= 1.3.1)
+  jekyll-sitemap (= 1.4.0)
   jekyll-time-to-read (= 0.1.2)
   nokogiri (= 1.10.5)
   rake (= 13.0.1)