[hotfix][doc] Update latest version of 2.1 as 2.1.1 (#27289)

Author: Zakelly

docs/config.toml

@@ -34,7 +34,7 @@ pygmentsUseClasses = true
   # we change the version for the complete docs when forking of a release branch
   # etc.
   # The full version string as referenced in Maven (e.g. 1.2.1)
-  Version = "2.1.0"
+  Version = "2.1.1"
 
   # For stable releases, leave the bugfix version out (e.g. 1.2). For snapshot
   # release this should be the same as the regular version