[ci] Fix auto-publishing gh-pages

https://github.com/github/hub/commit/24ba9063ab346d31f943ba889ca3c5a4b5b14c76/checks?check_suite_id=412011825

.github/workflows/release.yml

@@ -9,7 +9,7 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-    - uses: actions/checkout@v1
+    - uses: actions/checkout@v2
 
     - name: Set up Go
       uses: actions/setup-go@v1

script/publish-release

@@ -5,7 +5,6 @@ publish_documentation() {
   local version="$1"
   local doc_dir="site"
   local doc_branch="gh-pages"
-  local remote_url="$(git config remote.origin.url)"
 
   git fetch origin "${doc_branch}:${doc_branch}"
   git worktree add "$doc_dir" "$doc_branch"
@@ -23,8 +22,7 @@ publish_documentation() {
     GIT_AUTHOR_NAME='Mislav Marohnić' GIT_AUTHOR_EMAIL='mislav@github.com' \
     git commit -m "Update documentation for $version"
 
-  git push "https://${GITHUB_TOKEN}@${remote_url#https://}" HEAD
-
+  git push origin HEAD
   popd
 }