BREAKING CHANGE: remove Milvus1DocumentStore along with support for Milvus < 2.x

[masci]

Related Issues

• fixes n/a (going on, we should have an issue to schedule removal of deprecated components)

Proposed Changes:

• Remove support for Milvus 1.x
• Deprecate Milvus2DocumentStore in favor of MilvusDocumentStore [FIXME: link removal issue]

How did you test it?

Notes for the reviewer

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 tests that demonstrate the correct behavior of the change
• I've used the conventional commit convention for my PR title
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• I ran pre-commit hooks and fixed any issue

[masci]

Paging @ZanSara for reviewing the deprecation policy and @bogdankostic who did the heavy lifting.

[ZanSara]

Let's fix the deprecation warning situation before merging

[mayankjobanputra]

@masci I looked at the PR just out of curiosity... so Milvus2 doesn't require a separate docker and gets installed with the library itself?

[masci]

@mayankjobanputra uhm are you referring to the functions in utils/doc_store.py? Those are merely utility functions that you can use to orchestrate a bunch of docker containers through Haystack.

[ZanSara]

🚀 Let's merge this!