Deprecates "Add data from Splunk" without removing section (#3808)

Fixes elastic/docs-content-internal#403 by
removing the Add Data from Splunk page, which was deprecated in 9.0 This
was a technical preview feature, and the current docs are no longer
accurate; the functionality is no longer present starting from 9.0 per
@jamiehynds. Also removes links to that page, since we shouldn't be
directing users to a deprecated feature.

(Does not remove the "other tutorials" section that I proposed removing
in a previous PR).

Author: benironside

redirects.yml

@@ -206,7 +206,7 @@ redirects:
   'troubleshoot/elasticsearch/elasticsearch-client-net-api/logging.md': 'troubleshoot/elasticsearch/clients.md'
   'troubleshoot/elasticsearch/elasticsearch-client-net-api/net.md': 'troubleshoot/elasticsearch/clients.md'
   'troubleshoot/elasticsearch/elasticsearch-client-ruby-api/ruby.md': 'troubleshoot/elasticsearch/clients.md'
-  'solutions/observability/get-started/add-data-from-splunk.md': 'solutions/observability/get-started/other-tutorials/add-data-from-splunk.md'
+  'solutions/observability/get-started/add-data-from-splunk.md': 'solutions/observability/get-started.md'
   'solutions/observability/get-started/create-an-observability-project.md': 'solutions/observability/get-started.md'
   'solutions/observability/get-started/get-started-with-dashboards.md': 'solutions/observability/get-started.md'
 # Related to https://github.com/elastic/docs-content/pull/1329
@@ -586,4 +586,7 @@ redirects:
   'deploy-manage/monitor/autoops/cc-cloud-connect-autoops-faq.md': 'deploy-manage/monitor/autoops/ec-autoops-faq.md'
 
 # Related to https://github.com/elastic/docs-team/issues/104
-  'solutions/observability/get-started/what-is-elastic-observability': 'solutions/observability.md'
+  'solutions/observability/get-started/what-is-elastic-observability': 'solutions/observability.md'
+
+# Related to https://github.com/elastic/docs-content/pull/3808
+  'solutions/observability/get-started/other-tutorials/add-data-from-splunk.md': 'solutions/observability/get-started.md'

solutions/observability/get-started/other-tutorials/add-data-from-splunk.md

@@ -13,6 +13,5 @@ products:
 The following tutorials explore various use cases and {{observability}} scenarios.
 
 - [Tutorial: Monitor a Java application](/solutions/observability/get-started/other-tutorials/tutorial-monitor-java-application.md)
-- [Tutorial: Add data from Splunk](/solutions/observability/get-started/other-tutorials/add-data-from-splunk.md)
 
 To get started with {{observability}}, refer to [Get started with Elastic {{observability}}](/solutions/observability/get-started.md).

solutions/observability/get-started/other-tutorials/index.md

@@ -38,7 +38,6 @@ Want to use {{fleet}} or some other feature not covered in the quickstarts? Foll
 
 Ready to dig into more features of Elastic Observability? See these guides:
 
-* [Add data from Splunk](/solutions/observability/get-started/other-tutorials/add-data-from-splunk.md).
 * [Create an alert](/solutions/observability/incident-management/alerting.md).
 * [Create a service-level objective (SLO)](/solutions/observability/incident-management/create-an-slo.md).
 

solutions/observability/get-started/quickstarts.md

@@ -19,7 +19,6 @@ To ingest data, you can use:
 * The {{agent}} with integrations, which are available in the [Elastic Package Registry (EPR)](/reference/fleet/index.md#package-registry-intro). To install an integration that works with {{elastic-sec}}, go to the {{kib}} Home page or navigation menu and click **Add integrations**. On the Integrations page, click the **Security** category filter, then select an integration to view the installation instructions. For more information on integrations, refer to [{{integrations}}](https://docs.elastic.co/en/integrations).
 * **{{beats}}** shippers installed for each system you want to monitor.
 * **{{ls}}**, which dynamically ingests, transforms, and ships your data regardless of format.
-* The {{agent}} to send data from Splunk to {{elastic-sec}}. Refer to [Get started with data from Splunk](/solutions/observability/get-started/other-tutorials/add-data-from-splunk.md).
 * Third-party collectors configured to ship ECS-compliant data. [](/reference/security/fields-and-object-schemas/siem-field-reference.md) provides a list of ECS fields used in {{elastic-sec}}.
 
 ::::{important}

solutions/security/get-started/ingest-data-to-elastic-security.md

@@ -146,7 +146,6 @@ toc:
           - file: observability/get-started/other-tutorials/index.md
             children:
               - file: observability/get-started/other-tutorials/tutorial-monitor-java-application.md
-              - file: observability/get-started/other-tutorials/add-data-from-splunk.md
           - file: observability/get-started/logs-essentials.md
       - file: observability/applications/index.md
         children: