[main] (backport #13461) Add Elastic Agent 8.19.14 release notes

[mergify]

Adds Elastic Agent 8.19.14 release notes.

Checklist

• @ebeahan review this PR to make sure the correct items are included
• @elastic/ingest-docs review the language
• @elastic/ingest-docs open a PR in the ingest-docs repo combining the Elastic Agent and Fleet Server release notes targeting the 8.19 branch: Doc: Add Fleet and Agent release notes for 8.19.14 ingest-docs#1900
• @ebeahan merge or close on release day. No forward or backports are needed.

• Note: Release notes for 8.x versions are published from the ingest-docs repo. Merging this PR won't hurt, but it is unnecessary.

• @elastic/ingest-docs merge PR in the ingest-docs repo. No forward or backports are needed.

  ---

  This is an automatic backport of pull request Add Elastic Agent 8.19.14 release notes #13461 done by Mergify.

[mergify]

Cherry-pick of e556177 has failed:

On branch mergify/bp/main/pr-13461
Your branch is up to date with 'origin/main'.

You are currently cherry-picking commit e55617763.
  (fix conflicts and run "git cherry-pick --continue")
  (use "git cherry-pick --skip" to skip this patch)
  (use "git cherry-pick --abort" to cancel the cherry-pick operation)

Changes to be committed:
	new file:   changelog/8.19.14.asciidoc
	new file:   changelog/8.19.14.yaml
	deleted:    changelog/fragments/1758822287-bump-golang-1.25.8.yaml
	deleted:    changelog/fragments/1772715054-cloud-defend-procfs.yaml
	deleted:    changelog/fragments/1772815729-cloud-defend-helm-chart.yaml
	deleted:    changelog/fragments/1773697016-Prevent-zombie-processes-when-component-fails-to-shutdown.yaml
	deleted:    changelog/fragments/1773760327-fix-container-enrollment-to-not-re-enroll-when-the-fleet_url-is-the-same.yaml
	deleted:    changelog/fragments/1774382936-update-otel-to-v1.54.0-v0.148.0.yaml
	deleted:    changelog/fragments/1774970286-dependency-upgrade-nodejs-v22.22.2.yaml

Unmerged paths:
  (use "git add/rm <file>..." as appropriate to mark resolution)
	deleted by them: changelog/fragments/1770821590-update-otel-components-to-v0.145.0.yaml
	deleted by them: changelog/fragments/1771511114-add-opamp-extension-to-edot-collector.yaml
	deleted by them: changelog/fragments/1773394006-state-store-extension.yaml
	deleted by them: changelog/fragments/1773836790-update-otel-components-to-v0.147.0.yaml

To fix up this pull request, you can check it out locally. See documentation: https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/reviewing-changes-in-pull-requests/checking-out-pull-requests-locally