Remove speed metrics from default compute objective [WIP]

[shiva-z]

What does this PR do?

This PR removes speed metrics (e.g. eval_runtime) from the default compute objective (default_compute_objective). default_compute_objective is used when no compute_objective is passed to Trainer.hyperparameter_search. Trainer adds speed metrics such as eval_runtime and eval_samples_per_second to the metrics and default_compute_objective returns the sum of metrics as the objective so these speed metrics will be included in the objective.

I still need to add unit test for default_compute_objective to avoid having such metrics in the objective in the future.

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• This PR fixes a typo or improves the docs (you can dismiss the other checks if that's the case).
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• Did you write any new necessary tests?

Who can review?

@sgugger

[sgugger]

Oh boy, that is rather bad! Thanks a lot for fixing this!
Did you want to add the test in this PR?

[shiva-z]

Oh boy, that is rather bad! Thanks a lot for fixing this!
Did you want to add the test in this PR?

I can also create a follow up PR if you want to merge this asap. I can't implement the test cases right away. Maybe in ~4 days. @sgugger

[sgugger]

In that case maybe a follow-up PR, this fix is needed badly so I will merge. Thanks again!