ci: require docs to be fine

Build the documentation as part of PRs. Fail when something wrong is
found while building the docs.

Signed-off-by: Flavio Castelli <fcastelli@suse.com>

.github/workflows/tests.yml

@@ -48,6 +48,19 @@ jobs:
           command: test
           args: --workspace --features full-native-tls,test-registry
 
+  doc:
+    name: Build Documentation
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@a5ac7e51b41094c92402da3b24376905380afc29 # v4.1.6
+      - uses: actions-rs/toolchain@16499b5e05bf2e26879000db0c1d13f7e13fa3af # v1.0.7
+        with:
+          profile: minimal
+          toolchain: nightly
+          override: true
+      - run: |
+          make doc
+
   fmt:
     name: Rustfmt
     runs-on: ubuntu-latest

Makefile

@@ -12,7 +12,7 @@ lint:
 
 .PHONY: doc
 doc:
-	cargo doc
+	RUSTDOCFLAGS="--cfg docsrs -D warnings" cargo +nightly doc --all-features --no-deps
 
 .PHONY: test
 test: fmt lint doc