[DOCS] Tags discovery.ec2.protocol setting as removed in 9.1

[szabosteve]

Overview

Related to #122062

This PR adds an applies_to tag to the discovery.ec2.protocol setting to indicate that it will be removed in 9.1.

Note

As the markdown-based documentation is cumulative, we need to tag documentation sections to indicate their availability in the 9.x lifecycle. There is no longer a new documentation set published with every minor release; the same page remains valid over time and displays version-related updates. This is why the applies_to tags are used (in the page frontmatter, or inline).

Refer to the following pages for more information:

• docs versioning
• applies_to tags

[github-actions]

🔍 Preview links for changed docs

• docs/reference/elasticsearch-plugins/discovery-ec2-usage.md

[DaveCTurner]

Discussed in Slack, but for posterity this renders thusly:

After the 9.1.0 release it'll show Removed in 9.1.0.

That's perhaps not quite the right way to document this. This setting doesn't do anything in 9.1.0+ (hence why we didn't want to document it) but it still exists as a setting so it's not an error to set it. It's deprecated, but we will not remove it until 10.0.0.

[elasticsearchmachine]

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

[DaveCTurner]

So now it says Deprecation planned and I guess that means it'll eventually say Deprecated in 9.1.0? That's true, but only half the story. Typically when something is deprecated it continues to work (except with a warning) until it's removed, whereas this setting becomes a no-op from 9.1.0 onwards. If we have to document it, we should explain that difference in behaviour in the docs too.

[DaveCTurner]

LGTM

[elasticsearchmachine]

💚 Backport successful

Status	Branch	Result
✅	9.1