Bump the docs version to 8.16.6

Author: natasha-moore-elastic

shared/versions/stack/8.16.asciidoc

@@ -1,12 +1,12 @@
-:version:                8.16.5
+:version:                8.16.6
 ////
 bare_version never includes -alpha or -beta
 ////
-:bare_version:           8.16.5
-:logstash_version:       8.16.5
-:elasticsearch_version:  8.16.5
-:kibana_version:         8.16.5
-:apm_server_version:     8.16.5
+:bare_version:           8.16.6
+:logstash_version:       8.16.6
+:elasticsearch_version:  8.16.6
+:kibana_version:         8.16.6
+:apm_server_version:     8.16.6
 // branch is 8.16 instead of 8.x for long-term linking purposes
 :branch:                 8.16
 :minor-version:          8.16