Update antora-playbook.yml

removed 4.8.x branch since it is no longer the latest LTS
diff --git a/antora-playbook-snippets/antora-playbook.yml b/antora-playbook-snippets/antora-playbook.yml
index 7c58f08..a7432a5 100644
--- a/antora-playbook-snippets/antora-playbook.yml
+++ b/antora-playbook-snippets/antora-playbook.yml
@@ -57,7 +57,6 @@
       branches:
         - main
         - camel-kafka-connector-4.10.x
-        - camel-kafka-connector-4.8.x
       start_paths:
         - docs
         - connectors