Remove aws-lc-sys dependency

[stefnotch]

This ensures that cargo build --no-default-features -F update_check,rustls works as intended on Windows once again.
Fix #920

It's possible for users to opt-in into aws-lc-sys by depending on rustls themselves, and enabling the feature.

[ctron]

I absolutely like the idea of bringing back a sane rustls mode for cargo install.

However, I think it would make sense to default trunk's build to just cargo install. and have openssl used with cargo install --no-default-features -F openssl. And it someone wants aws-lc-sys, then have cargo install --no-default-features -F rustls-awc-lc.

[stefnotch]

Glad to hear that you also think so!

I figured I'd put the most critical tweak into this PR, and then open another PR that changes the default to be rustls without aws. As in, this should be ready to merge right away.

[ctron]

I'd prefer to have a single PR and release this right away. I'd consider this an (un)breaking change :)

[stefnotch]

I have changed Trunk's default to use rustls without aws-lc-sys.
With rustls-aws-lc, one can opt ino the aws-lc-sys. And with native-tls one can opt into OpenSSL.