build: use purple merge instead of close on CQ

If the bot can make modifications to the head branch, force push to the
head branch so it lands with the purple icon on GitHub instead of the
red icon when the PR is closed. Let's gooooooooo!

Ref: nodejs/node-core-utils#264

tools/actions/commit-queue.sh

@@ -14,6 +14,10 @@ API_URL=https://api.github.com
 COMMIT_QUEUE_LABEL='commit-queue'
 COMMIT_QUEUE_FAILED_LABEL='commit-queue-failed'
 
+function prUrl() {
+  echo "$API_URL/repos/${OWNER}/${REPOSITORY}/pulls/${1}"
+}
+
 function issueUrl() {
   echo "$API_URL/repos/${OWNER}/${REPOSITORY}/issues/${1}"
 }
@@ -80,13 +84,21 @@ for pr in "$@"; do
     git node land --abort --yes
   else
     rm output
+    head=$(gitHubCurl "$(prUrl "$pr")" GET | jq '{ ref: .head.ref, remote: .head.repo.ssh_url, can_modify: .maintainer_can_modify }')
+    if [ "$(echo "$head" | jq -r .can_modify)" == "true" ]; then
+      git push --force "$(echo "$head" | jq -r .remote)" master:"$(echo "$head" | jq -r .ref)"
+      # Give GitHub time to sync before pushing to master
+      sleep 60s
+    fi
 
     commits="$(git rev-parse $UPSTREAM/$DEFAULT_BRANCH)...$(git rev-parse HEAD)"
 
     git push $UPSTREAM $DEFAULT_BRANCH
 
     gitHubCurl "$(commentsUrl "$pr")" POST --data '{"body": "Landed in '"$commits"'"}'
 
-    gitHubCurl "$(issueUrl "$pr")" PATCH --data '{"state": "closed"}'
+    if [ "$(echo "$head" | jq -r .can_modify)" != "true" ]; then
+      gitHubCurl "$(issueUrl "$pr")" PATCH --data '{"state": "closed"}'
+    fi
   fi
 done