Use the latest nightly rust to run linkcheck (rust-lang#14348)

changelog: none

Author: flip1995

.github/workflows/remark.yml

@@ -37,6 +37,7 @@ jobs:
     - name: Linkcheck book
       run: |
         rustup toolchain install nightly --component rust-docs
+        rustup override set nightly
         curl https://raw.githubusercontent.com/rust-lang/rust/master/src/tools/linkchecker/linkcheck.sh -o linkcheck.sh
         sh linkcheck.sh clippy --path ./book