Update CI config (#650)

ci/test-stable.sh

@@ -4,10 +4,6 @@ set -ex
 
 cmd="${1:-test}"
 
-# Install cargo-hack for feature flag test
-host=$(rustc -Vv | grep host | sed 's/host: //')
-curl -LsSf https://github.com/taiki-e/cargo-hack/releases/latest/download/cargo-hack-$host.tar.gz | tar xzf - -C ~/.cargo/bin
-
 # Run with each feature
 # * --each-feature includes both default/no-default features
 # * --optional-deps is needed for serde feature
@@ -15,8 +11,6 @@ cargo hack "${cmd}" --each-feature --optional-deps
 # Run with all features
 cargo "${cmd}" --all-features
 
-cargo doc --no-deps --all-features
-
 if [[ "${RUST_VERSION}" == "nightly"* ]]; then
     # Check benchmarks
     cargo check --benches