fix: trainer client backend public

[jaiakash]

What this PR does / why we need it:
This PR makes the backend attribute in TrainerClient publicly accessible. Currently, it is private, which restricts users from programmatically interacting with the underlying backend. Exposing it allows developers to extend functionality, debug, or customize backend usage more easily.

Fixes #77

Checklist:

• Docs included if any changes are user facing

[coveralls]

Pull Request Test Coverage Report for Build 17340436659

Details

• 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 65.033%

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Totals
Change from base Build 17296779530:	0.0%
Covered Lines:	292
Relevant Lines:	449

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💛 - Coveralls

[andreyvelich]

Thanks @jaiakash! I think, we should make backend public, so users can access values of TrainerClient().
/lgtm
/assign @szaher @kramaranya @astefanutti

[kramaranya]

I agree we should keep it public. Thank you @jaiakash!
/lgtm

[kramaranya]

We probably shall add alpaca notebook to the e2e, so we cover this functionality as well, wdyt? @andreyvelich @jaiakash

[andreyvelich]

We probably shall add alpaca notebook to the e2e, so we cover this functionality as well, wdyt? @andreyvelich @jaiakash

We are working on it as part of, which enables testing on GPUs: kubeflow/trainer#2762

[andreyvelich]

/approve

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[jaiakash]

Thanks @andreyvelich @kramaranya
I am already working on it as part of, which enables testing on GPUs: kubeflow/trainer#2762