Use native-tls/native-certs features of ureq crate

[lazareviczoran]

Hello!

We use this crate on one of our projects, once we bumped it to version 0.10.7, we started getting failures for the license checks in cargo-deny, since openblas-build now uses ureq for downloading the openblas source, which brings in a dependency with a MPL-2.0 license to the Cargo.lock file (it has been brought up in ureq repo as well algesten/ureq#478).

ureq does have some feature flags that provide the possibility to use native-tls, the lib doesn't implement the default tls config when using native-tls feature flag (https://github.com/algesten/ureq/blob/main/src/lib.rs#L377-L397), but it allows to setup an agent explicitly by providing the tls config (as it is done in this test https://github.com/algesten/ureq/blob/main/src/lib.rs#L583-L595).
There was a proposal for adding feature flag in ureq that includes rustls with the native-certs flag so that the default agent can work with the native-certs (algesten/ureq#482), but it was rejected, so currently it is not possible to just tweak the feature flags on ureq and exclude the unwanted sub-dependencies.

The idea of this PR is to add feature flags to openblas-src and openblas-build that allows users to choose which tls config they want to use. This PR introduces 2 feature flags (tls which includes the default tls that ureq uses, and native-certs which uses native-tls and native-certs feature flags in ureq).
The default flags are set to use the tls feature flag, but worth to note is that this would probably be a breaking change when the default features are disabled and neither of these flags are enabled.

Any thoughts on this?
I look forward to you feedback!

[termoshtt]

Thanks PR!

Using native-certs crate looks better for keeping dependencies list simple.

The default flags are set to use the tls feature flag, but worth to note is that this would probably be a breaking change when the default features are disabled and neither of these flags are enabled.

To avoid this issue, we should use only native-certs case without introducing the feature flag.

[lazareviczoran]

Thanks PR!

Using native-certs crate looks better for keeping dependencies list simple.

The default flags are set to use the tls feature flag, but worth to note is that this would probably be a breaking change when the default features are disabled and neither of these flags are enabled.

To avoid this issue, we should use only native-certs case without introducing the feature flag.

Thanks for the feedback 🙌
I've removed the introduced feature flags and updated the PR to use native-certs by default as you suggested.

[termoshtt]

0.10.8 has been released with this PR https://github.com/blas-lapack-rs/openblas-src/releases/tag/openblas-src-v0.10.8