ESQL - Fix source loader filter when vectors are excluded

[carlosdelest]

Closes #145799

Fixes a performance issue for source filtering. When dense vector fields are excluded from source, and there are other source paths inclusions, the whole source (except dense vector fields) is loaded instead of using the source inclusion mechanism.

[elasticsearchmachine]

Hi @carlosdelest, I've created a changelog YAML for you.

[github-actions]

🔍 Preview links for changed docs

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This comment will be updated with preview links when the build is complete.

[github-actions]

ℹ️ Important: Docs version tagging

👋 Thanks for updating the docs! Just a friendly reminder that our docs are now cumulative. This means all 9.x versions are documented on the same page and published off of the main branch, instead of creating separate pages for each minor version.

We use applies_to tags to mark version-specific features and changes.

Expand for a quick overview

When to use applies_to tags:

✅ At the page level to indicate which products/deployments the content applies to (mandatory)
✅ When features change state (e.g. preview, ga) in a specific version
✅ When availability differs across deployments and environments

What NOT to do:

❌ Don't remove or replace information that applies to an older version
❌ Don't add new information that applies to a specific version without an applies_to tag
❌ Don't forget that applies_to tags can be used at the page, section, and inline level

🤔 Need help?

• Check out the cumulative docs guidelines
• Reach out in the #docs Slack channel

[elasticsearchmachine]

Pinging @elastic/es-search-relevance (Team:Search Relevance)

[elasticsearchmachine]

💔 Backport failed

Status	Branch	Result
✅	9.4
❌	9.3	Commit could not be cherrypicked due to conflicts

You can use sqren/backport to manually backport by running backport --upstream elastic/elasticsearch --pr 146223

[carlosdelest]

💚 All backports created successfully

Status	Branch	Result
✅	9.3

Questions ?

Please refer to the Backport tool documentation