Remove links to Journalbeat (#29134) (#29136)

(cherry picked from commit 8e6345f)

Co-authored-by: DeDe Morton <[email protected]>

libbeat/docs/getting-started.asciidoc

@@ -7,7 +7,6 @@ Each Beat is a separately installable product. To learn how to get started, see:
 * {filebeat-ref}/filebeat-installation-configuration.html[Filebeat]
 * {functionbeat-ref}/functionbeat-installation-configuration.html[Functionbeat]
 * {heartbeat-ref}/heartbeat-installation-configuration.html[Heartbeat]
-* {journalbeat-ref}/journalbeat-installation-configuration.html[Journalbeat]
 * {metricbeat-ref}/metricbeat-installation-configuration.html[Metricbeat]
 * {packetbeat-ref}/packetbeat-installation-configuration.html[Packetbeat]
 * {winlogbeat-ref}/winlogbeat-installation-configuration.html[Winlogbeat]

libbeat/docs/overview.asciidoc

@@ -11,7 +11,6 @@ Audit data:: https://www.elastic.co/products/beats/auditbeat[Auditbeat]
 Log files:: https://www.elastic.co/products/beats/filebeat[Filebeat]
 Cloud data:: https://www.elastic.co/products/beats/functionbeat[Functionbeat]
 Availability:: https://www.elastic.co/products/beats/heartbeat[Heartbeat]
-Systemd journals:: https://www.elastic.co/downloads/beats/journalbeat[Journalbeat]
 Metrics:: https://www.elastic.co/products/beats/metricbeat[Metricbeat]
 Network traffic:: https://www.elastic.co/products/beats/packetbeat[Packetbeat]
 Windows event logs:: https://www.elastic.co/products/beats/winlogbeat[Winlogbeat]