Remove hook-class-names from provider.yaml

[eladkal]

now that providers>=2.2 there is no need for the hook-class-names any longer.
refrence to #17775

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[potiuk]

One more thing - hook-class-names should also be removed from airflow/provider.yaml.schema.json and provider_info.schema.json

[github-actions]

The PR is likely OK to be merged with just subset of tests for default Python and Database versions without running the full matrix of tests, because it does not modify the core of Airflow. If the committers decide that the full tests matrix is needed, they will add the label 'full tests needed'. Then you should rebase to the latest main or amend the last commit of the PR, and push it with --force-with-lease.

[potiuk]

As discussed on slack:

• we should only remove hook-class-names from provider.yaml.schema and our provider.yamls
• we should leave it in provider_info.schema and continue raising deprecation warnings if a 3rd-party provider uses hook-class-names

[eladkal]

Update:
After talking to @potiuk

We are not looking to remove the feature but only remove the usage of the feature from Airflow providers.
Thus i'm changing provider.yaml.schema.json but not provider_info.schema.json since users may still use it should they want to create 3rd party custom providers for Airflow<2.2 - This is why I'm also not removing documentation of the feature from rst files

[eladkal]

@potiuk I think we are ready here :)

[potiuk]

I ❤️ code removal !

[potiuk]