chore(doc): Replace doc_auto_cfg config with doc_cfg (#2428)

## Motivation

`doc_auto_cfg` was merged into `doc_cfg` in
rust-lang/rust#138907.

## Solution

Replaces `doc_auto_cfg` config with `doc_cfg`. And uses `cargo-docs-rs`
to check with the same options used by docs.rs.

Author: tottoto

.github/workflows/CI.yml

@@ -308,7 +308,16 @@ jobs:
     - uses: Swatinem/rust-cache@v2
     # we exlude crates that do not use rust-version = { workspace = true }
     - run: cargo no-dev-deps --no-private check --all-features --workspace --exclude grpc --exclude tonic-protobuf\*
-    - run: cargo no-dev-deps --no-private doc --no-deps --all-features --workspace --exclude grpc --exclude tonic-protobuf\*
+
+  doc:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v5
+    - uses: dtolnay/rust-toolchain@nightly
+    - uses: dtolnay/install@cargo-docs-rs
+    - uses: taiki-e/install-action@cargo-hack
+    - uses: Swatinem/rust-cache@v2
+    - run: cargo +nightly hack --no-private docs-rs
       env:
         RUSTDOCFLAGS: "-D warnings"
 

tonic-build/src/lib.rs

@@ -5,7 +5,7 @@
 )]
 #![doc(issue_tracker_base_url = "https://github.com/hyperium/tonic/issues/")]
 #![doc(test(no_crate_inject, attr(deny(rust_2018_idioms))))]
-#![cfg_attr(docsrs, feature(doc_auto_cfg))]
+#![cfg_attr(docsrs, feature(doc_cfg))]
 
 use proc_macro2::{Delimiter, Group, Ident, Literal, Punct, Spacing, Span, TokenStream};
 use quote::TokenStreamExt;

tonic-health/src/lib.rs

@@ -11,7 +11,7 @@
 )]
 #![doc(issue_tracker_base_url = "https://github.com/hyperium/tonic/issues/")]
 #![doc(test(no_crate_inject, attr(deny(rust_2018_idioms))))]
-#![cfg_attr(docsrs, feature(doc_auto_cfg))]
+#![cfg_attr(docsrs, feature(doc_cfg))]
 
 use std::fmt::{Display, Formatter};
 

tonic-reflection/src/lib.rs

@@ -5,7 +5,7 @@
 )]
 #![doc(issue_tracker_base_url = "https://github.com/hyperium/tonic/issues/")]
 #![doc(test(no_crate_inject, attr(deny(rust_2018_idioms))))]
-#![cfg_attr(docsrs, feature(doc_auto_cfg))]
+#![cfg_attr(docsrs, feature(doc_cfg))]
 
 mod generated {
     #![allow(unreachable_pub)]

tonic/src/lib.rs

@@ -97,7 +97,7 @@
 )]
 #![doc(issue_tracker_base_url = "https://github.com/hyperium/tonic/issues/")]
 #![doc(test(no_crate_inject, attr(deny(rust_2018_idioms))))]
-#![cfg_attr(docsrs, feature(doc_auto_cfg))]
+#![cfg_attr(docsrs, feature(doc_cfg))]
 
 pub mod body;
 pub mod client;