Clean up g_proximal arguments

[tkoskela]

Closes actions/setup-python#298

Pass beta and phi through constructor of g_proximal and pass them to arguments of l1_proximal internally when the proximal function is called. Remove them from call in forward_backward in preparation for other (TF) g_proximal implementations.

[tkoskela]

We fail test_forward_backward because I've changed the call signature of g_proximal. In the test, g_proximal is proximal::id:

sopt/cpp/sopt/proximal.h

Lines 136 to 139 in d45d533

	void id(Eigen::DenseBase<T0> &out, typename real_type<typename T0::Scalar>::type gamma,
	Eigen::DenseBase<T1> const &x) {
	out = x;
	}

so the difference here is what we pass in as x.

[tkoskela]

I would like to pass beta and Phi through setters of the l1_proximal rather than the constructor.

[tkoskela]

Nothing says happy 2023 like all MacOS tests failing for no reason! It seems we are affected by actions/runner-images#11545 looks like people are actively working to fix it so maybe it'll be resolved soon 🤞

[SJaffa]

Code looks good, I just suggested some tidying and comments.

The MacOS g++ tests are failing with error:
ConanException: sha256 signature failed for 'jpegsrc.v9e.tar.gz' file.

Is that to do with the homebrew issue you mentioned?

[tkoskela]

The MacOS g++ tests are failing with error:
ConanException: sha256 signature failed for 'jpegsrc.v9e.tar.gz' file.

I managed to work around the homebrew issue by skipping brew update, then ran into that and made a note of it in #327.

It looks like it might have been updated 12 hours ago conan-io/conan-center-index#15093