ci: Add job for ES8 integration tests

[bogdankostic]

Related Issues

• related to Make ElasticsearchDocumentStore compatible with ES8 #5027
• depends on build: Add elasticsearch7 and elasticsearch8 extra #5296

Proposed Changes:

This PR renames the job integration-tests-elasticsearch to integration-tests-elasticsearch7 and lets it run using Elasticsearch 7.17.6 to test es7.ElasticsearchDocumentStore.

Furthermore, it adds the job integration-tests-elasticsearch8 which installs the installation extra elasticsearch8 and, therefore, uses es8.ElasticsearchDocumentStore for the integration tests using Elasticsearch 8.8.0.

How did you test it?

Notes for the reviewer

This PR depends on #5296.

Checklist

• I have read the contributors guidelines and the code of conduct
• I have updated the related issue with new insights and changes
• I added unit tests and updated the docstrings
• I've used one of the conventional commit types for my PR title: fix:, feat:, build:, chore:, ci:, docs:, style:, refactor:, perf:, test:.
• I documented my code
• I ran pre-commit hooks and fixed any issue

[coveralls]

Pull Request Test Coverage Report for Build 5505708540

• 0 of 0 changed or added relevant lines in 0 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage remained the same at 44.789%

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Totals
Change from base Build 5505551393:	0.0%
Covered Lines:	10328
Relevant Lines:	23059

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💛 - Coveralls