[DOCS] Remove duplicate section title

[lcawl]

Summary

This PR addresses the following build error:

INFO:build_docs:asciidoctor: WARNING: CHANGELOG.asciidoc: line 110: id assigned to block already in use: known-issues-8.14.3

Which seems to have occurred when #189236 and #189331 merged updates to that section in close proximity.

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[obltmachine]

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Just comment with:

• /oblt-deploy : Deploy a Kibana instance using the Observability test environments.
• run docs-build : Re-trigger the docs validation. (use unformatted text in the comment!)

[kilfoyle]

LGTM! 🦝

[elasticmachine]

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

[lcawl]

/ci

[kibana-ci]

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