feat: switch from native-tls to rustls

[iamwacko]

Description of change

This PR changes native-tls to rustls on almost all of our dependencies. cargo-edit still technically depends on native-tls, but that is because it uses native-tls on architectures unsupported by rustls. Thanks to our dependency on cargo OpenSSL is still in the dependency tree, so I will hold off on actually merging this until the cargo library is completely removed, by me or someone else. Closes issue #873.

How Has This Been Tested (if applicable)?

It should just work, but I did compile and run it successfully. To check that native-tls wasn't anywhere in the dependency tree I ran cargo tree --target all -i native-tls.

[oddgrd]

Cool! I'm curious if we will have similar issues with other crates in the future if we don't use native-tls 🤔

By the way we use the vendored-openssl feature flag in our CI in a few places, this should also be updated. 🙏

[iamwacko]

#821 strikes again.

[oddgrd]

This LGTM except for one small comment!

[jonaro00]

Still waiting for #888 to remove cargo-edit for this to complete, right?

[iamwacko]

Still waiting for #888 to remove cargo-edit for this to complete, right?

Sort of, but not really. native-tls will still show up in the cargo tree, but it won't be compiled unless

[target.'cfg(not(any(target_arch = "x86_64", target_arch = "arm", target_arch = "x86", target_arch = "aarch64")))'.dependencies]`

See line 89 of this. What this means is that in practice native-tls is gone and OpenSSL with it.

[oddgrd]

Thanks!