docker-py fix: fix(store): warn on init instead of throw

[felixfontein]

SUMMARY

Cherry-picked docker/docker-py#3080.

Using the proper ansible-core mechanisms for warnings instead of import warnings resulted in a lot of extra code.

Ref: #435

ISSUE TYPE

• Bugfix Pull Request

COMPONENT NAME

vendored Docker SDK for Python

[kristianheljas]

I have a few issues with this one:

1. warn argument is ambiguous - I was surprised when i discovered that it's a function, not a boolean.
2. Mere presence of the warning function will suppress an exception in Store.__init().
3. It's gonna fail with the same message in Store._execute() anyway so I can't see any advantage for the warning.

What are your thoughts about just silencing the InitializationError via explicit argument - validate_program_path=False for example?

[felixfontein]

Let's close this, as it isn't really needed anyway.