Post-migration Security Dashboards cleanup (#622)

Cleans up the Security Dashboards section, including both the
lift-and-shift and align serverless / stateful pages.

Affects the dashboards section:
[preview](https://docs-v3-preview.elastic.dev/elastic/docs-content/pull/622/solutions/security/dashboards)

---------

Co-authored-by: Nastasha Solomon <[email protected]>

Author: benironside

raw-migrated-files/docs-content/serverless/security-dashboards-overview.md

@@ -210,24 +210,19 @@ toc:
       - file: docs-content/serverless/security-cspm-get-started.md
       - file: docs-content/serverless/security-cspm-security-posture-faq.md
       - file: docs-content/serverless/security-cspm.md
-      - file: docs-content/serverless/security-dashboards-overview.md
-      - file: docs-content/serverless/security-data-quality-dash.md
       - file: docs-content/serverless/security-detection-engine-overview.md
-      - file: docs-content/serverless/security-detection-response-dashboard.md
       - file: docs-content/serverless/security-detections-requirements.md
       - file: docs-content/serverless/security-environment-variable-capture.md
       - file: docs-content/serverless/security-get-started-with-kspm.md
       - file: docs-content/serverless/security-interactive-investigation-guides.md
       - file: docs-content/serverless/security-kspm.md
       - file: docs-content/serverless/security-llm-connector-guides.md
       - file: docs-content/serverless/security-llm-performance-matrix.md
-      - file: docs-content/serverless/security-overview-dashboard.md
       - file: docs-content/serverless/security-posture-faq.md
       - file: docs-content/serverless/security-posture-management.md
       - file: docs-content/serverless/security-prebuilt-rules-management.md
       - file: docs-content/serverless/security-query-alert-indices.md
       - file: docs-content/serverless/security-reduce-notifications-alerts.md
-      - file: docs-content/serverless/security-rule-monitoring-dashboard.md
       - file: docs-content/serverless/security-rules-coverage.md
       - file: docs-content/serverless/security-rules-create.md
       - file: docs-content/serverless/security-rules-ui-management.md

raw-migrated-files/docs-content/serverless/security-data-quality-dash.md

@@ -6,13 +6,6 @@ mapped_urls:
 
 # Dashboards
 
-% What needs to be done: Lift-and-shift
-
-% Use migrated content from existing pages that map to this page:
-
-% - [x] ./raw-migrated-files/security-docs/security/dashboards-overview.md
-% - [ ] ./raw-migrated-files/docs-content/serverless/security-dashboards-overview.md
-
 The {{security-app}}'s default dashboards provide useful visualizations of your security environment. To view them in {{elastic-sec}}, select **Dashboards** from the navigation menu. From the Dashboards page, you can access the default dashboards, as well as create and access custom dashboards.
 
 To create a new custom dashboard, click **Create Dashboard**. You can control which custom dashboards appear in the table: