[Hotfix][ElasticsearchSink]Update the version in the docs.

[lightzhao]

Purpose of this pull request

The test found that the 6.x version cannot be supported.

Check list

• Code changed are covered with tests, or it does not need tests for reason:
• If any new Jar binary package adding in your PR, please add License Notice according
  New License Guide
• If necessary, please update the documentation to describe the new feature. https://github.com/apache/incubator-seatunnel/tree/dev/docs
• If you are contributing the connector code, please check that the following files are updated:
  1. Update change log that in connector document. For more details you can refer to connector-v2
  2. Update plugin-mapping.properties and add new connector information in it
  3. Update the pom file of seatunnel-dist
• Update the release-note.

[TyrantLucifer]

@iture123 PTAL

[lightzhao]

@iture123 @TyrantLucifer @Hisoka-X PTAL,thanks.

[TyrantLucifer]

The owner @iture123 of es connector has the different thoughts of this, later he will left his advice.

[iture123]

ElasticsearchRowSerializer make an error annotation,The elasticsearch connector and the class ElasticsearchRowSerializer.java both support ElasticSearch version is >= 2.x and <= 8.x.

[lightzhao]

error annotation,

ok, fix error annotation.

[lightzhao]

@TyrantLucifer @iture123 @Hisoka-X PTAL.

[lightzhao]

who has time help review, thanks.

[TyrantLucifer]

merge dev into your branch

[lightzhao]

merge dev into your branch

done.

[EricJoy2048]

@TyrantLucifer @iture123 @Hisoka-X PTAL again.