Allow upgrading elasticsearch ruby client and remove its 7.x patch logics.

[mashhurs]

This PR drops a support for Logstash 7.x although plugin still can be installed.

• removes elasticsearch 7.x specific patch logics
• allow upgrading elasticsearch ruby client up to 9.x versions

[github-actions]

Changelog and Version Management

No changelog or version changes detected. You can either update them manually or use a comment command to update them automatically on merge:

/pr_prepare release:<patch|minor|major> — bump version + update changelog
/pr_prepare changelog:add — changelog entry only (no version bump)

/pr_prepare release:patch
- Add the changelog entry here
  - (Additional details can be provided in multiple lines, respecting markdown formatting)

Omit the entry line to use the PR title. If multiple commands are posted, the last one wins.

[mashhurs]

/pr_prepare release: minor

• Drop a support for Logstash 7.x by requiring elasticsearch gem >= 8. Logstash 8+ continues to work as before.

[kaisecheng]

Thanks for the cleanup! One concern on the version bump. I believe it should be at least a 'minor' because upgrading gem version is not a bug fix and this change will block 7.17 user to install. I tested in 7.17.25 and confirmed that user can still install es-input 5.2.2.

I'd suggest minor/ major with a note in the changelog

  - Drop support for Logstash 7.x by requiring `elasticsearch` gem >= 8.
    Logstash 8+ continues to work as before.

[mashhurs]

Thanks for the cleanup! One concern on the version bump. I believe it should be at least a 'minor' because upgrading gem version is not a bug fix and this change will block 7.17 user to install. I tested in 7.17.25 and confirmed that user can still install es-input 5.2.2.

I'd suggest minor/ major with a note in the changelog

  - Drop support for Logstash 7.x by requiring `elasticsearch` gem >= 8.
    Logstash 8+ continues to work as before.

Yep, just updated the changelog/version-bump request. As we discussed in the weekly, I will add release note when this change will be embedded in LS core and I have opened an issue if there anything more we need follow up - #254

[kaisecheng]

LGTM