Enable feature(doc_auto_cfg)

[ctz]

This removes duplicated manual feature gates for documentation and leaves it to cargo doc to derive the same information from the actual feature gates.

I didn't find any gaps in the auto-generated features and what we had before, but now things like rustls::cipher_suite::TLS_ECDHE_* are correctly marked tls12-only.

fixes #1393

[codecov]

Codecov Report

Merging #1395 (3c9eea0) into main (f5837b0) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##             main    #1395   +/-   ##
=======================================
  Coverage   96.32%   96.32%           
=======================================
  Files          64       64           
  Lines       14734    14734           
=======================================
  Hits        14193    14193           
  Misses        541      541           

Files Changed	Coverage Δ
rustls/src/client/client_conn.rs	88.32% <ø> (ø)
rustls/src/conn.rs	92.65% <ø> (ø)
rustls/src/server/server_conn.rs	87.41% <ø> (ø)
rustls/src/suites.rs	97.79% <ø> (ø)
rustls/src/verify.rs	63.63% <ø> (ø)
rustls/src/webpki/verify.rs	98.69% <ø> (ø)

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[ctz]

(i think we should do this in the webpki crate too)

[cpu]

This isn't from your diff, but I noticed while validating the change locally that we have a rustdoc warning:

warning: unresolved link to `ConfigBuilder::with_custom_certificate_verifier`
  --> rustls/src/builder.rs:71:10
   |
71 | ///  - [`ConfigBuilder::with_custom_certificate_verifier`] - requires dangerous_configuration feature flag
   |          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the struct `ConfigBuilder` has no field or associated item named `with_custom_certificate_verifier`
   |
   = note: `#[warn(rustdoc::broken_intra_doc_links)]` on by default

Would you be open to fixing that in this branch? (also might be worth a CI tweak to fail closed on warnings.)

[ctz]

Would you be open to fixing that in this branch? (also might be worth a CI tweak to fail closed on warnings.)

Ah, so we do have -Dwarnings (deny warnings) on the cargo doc job, but also that uses --all-features (which makes ConfigBuilder::with_custom_certificate_verifier appear, and so the warning disppears).

The interesting question is whether there's a notation in cargo doc that means "link to this if it's compiled in"?

[cpu]

Ah, so we do have -Dwarnings (deny warnings) on the cargo doc job, but also that uses --all-features

Oooh, that makes sense.

[ctz]

Have raised rust-lang/rust#114626 to discuss that