Clean up tests to diagnose Frank-Wolfe linear solver error

[gdalle]

• Revert specification of test dependencies to the more robust version (see this issue)
• Adjust default parameters for Frank-Wolfe (increase precision and switch step size selection) because a recent release or FrankWolfe.jl broke our tests (see #40)
• Deactivate test verbosity to make CI logs easier to read
• Switch data to Float32 to suppress Flux.jl warning
• Try to parallelize tests but they no longer show up in the test set so I gave up (see this discourse thread, it seems like an open problem)

[codecov-commenter]

Codecov Report

Patch coverage: 25.00% and project coverage change: -0.27 :warning:

Comparison is base (49dfd06) 89.26% compared to head (a840f89) 89.00%.

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Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #39 +/- ## ========================================== - Coverage 89.26% 89.00% -0.27% ========================================== Files 18 18 Lines 382 382 ========================================== - Hits 341 340 -1 - Misses 41 42 +1 ``` | [Impacted Files](https://codecov.io/gh/axelparmentier/InferOpt.jl/pull/39?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=None) | Coverage Δ | | |---|---|---| | [src/frank\_wolfe/frank\_wolfe\_utils.jl](https://codecov.io/gh/axelparmentier/InferOpt.jl/pull/39?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=None#diff-c3JjL2ZyYW5rX3dvbGZlL2ZyYW5rX3dvbGZlX3V0aWxzLmps) | `83.33% <ø> (ø)` | | | [src/frank\_wolfe/differentiable\_frank\_wolfe.jl](https://codecov.io/gh/axelparmentier/InferOpt.jl/pull/39?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=None#diff-c3JjL2ZyYW5rX3dvbGZlL2RpZmZlcmVudGlhYmxlX2ZyYW5rX3dvbGZlLmps) | `93.75% <25.00%> (-6.25%)` | :arrow_down: | ... and [2 files with indirect coverage changes](https://codecov.io/gh/axelparmentier/InferOpt.jl/pull/39/indirect-changes?src=pr&el=tree-more&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=None) Help us with your feedback. Take ten seconds to tell us [how you rate us](https://about.codecov.io/nps?utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=None). Have a feature suggestion? [Share it here.](https://app.codecov.io/gh/feedback/?utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=None)

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[gdalle]

@BatyLeo maybe switching to agnostic step size is not a good idea, see https://github.com/ZIB-IOL/FrankWolfe.jl/issues/387#issuecomment-1449603456

Let's wait a bit before we merge

[BatyLeo]

@BatyLeo maybe switching to agnostic step size is not a good idea, see ZIB-IOL/FrankWolfe.jl#387 (comment)

Let's wait a bit before we merge

Ok :+1: