[8.x] Updates "Cloud native security" to "Cloud security" (backport #6175)

[mergify]

Fixes #6170 — minor changes on several pages. We are no longer providing only "Native" cloud security (we're using 3rd party data as well as providing our own integrations). This PR updates language on several pages accordingly. Please refer to the diff for changes.

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This is an automatic backport of pull request #6175 done by Mergify.

[mergify]

Cherry-pick of 863c54f has failed:

On branch mergify/bp/8.x/pr-6175
Your branch is up to date with 'origin/8.x'.

You are currently cherry-picking commit 863c54f9.
  (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:
	modified:   docs/cloud-native-security/cloud-native-security-index.asciidoc
	modified:   docs/es-overview.asciidoc

Unmerged paths:
  (use "git add/rm <file>..." as appropriate to mark resolution)
	deleted by us:   docs/serverless/cloud-native-security/cloud-native-security-overview.asciidoc
	deleted by us:   docs/serverless/security-overview.asciidoc

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

[github-actions]

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