Review, remove unnecessary Serverless documentation links

[lcawl]

Relates to #167088

When I worked on moving hard-coded doc links into the doc link service (#88107) I didn't really put time into questioning whether the doc link should exist, I just fixed how it was coded.

As part of finding Serverless-specific documentation links for the keywords in kbn-doc-links, it's worth revisiting whether all of them add value. Could they be removed? Or are they indications that we need more detailed in-place help?

Though this work can affect both classic and serverless UIs, the first priority is to review the links in Serverless apps. For example, in Elasticsearch projects:

• Discover / Log explorer
• Dashboards
• Project settings / Management apps
  • Advanced settings
  • API keys
  • Connectors
  • Data views
  • Files N/A
  • Index management
  • Ingest pipelines
  • Logstash pipelines
  • Machine learning
  • Maintenance windows
  • Reports N/A
  • Rules
  • Saved objects N/A
  • Tags N/A
  • Transforms
• Visualizations

NOTE: In some cases the only place a documentation link appears is in the Help menu, but IMO those are still worth revisiting.

[elasticmachine]

Pinging @elastic/kibana-docs (Team:Docs)