[bots] Remove ciflow labels on sync if no perms, follow up to #6328 (#6342)

Follow up to #6328

Remove the ciflow labels on sync to reduce confusion

Cons:
* add more events to the PR timeline

Author: clee2000

torchci/lib/bot/ciflowPushTrigger.ts

@@ -92,6 +92,16 @@ async function handleSyncEvent(
 
   if (!(await canRunWorkflows(context as any))) {
     context.log.info("PR does not have permissions to run workflows");
+    for (const label of payload.pull_request.labels) {
+      if (isCIFlowLabel(label.name)) {
+        await context.octokit.issues.removeLabel(
+          context.repo({
+            issue_number: payload.pull_request.number,
+            name: label.name,
+          })
+        );
+      }
+    }
     return;
   }
 

torchci/test/ciflow-push-trigger.test.ts

@@ -9,6 +9,16 @@ import {
 
 nock.disableNetConnect();
 
+function mockDeleteLabel(repoFullName: string, number: number, label: string) {
+  return nock("https://api.github.com")
+    .delete(
+      `/repos/${repoFullName}/issues/${number}/labels/${encodeURIComponent(
+        label
+      )}`
+    )
+    .reply(200);
+}
+
 describe("Push trigger integration tests", () => {
   let probot: Probot;
   beforeEach(() => {
@@ -238,6 +248,16 @@ describe("Push trigger integration tests", () => {
       payload.pull_request.user.login,
       "read"
     );
+    mockDeleteLabel(
+      payload.repository.full_name,
+      payload.pull_request.number,
+      "ciflow/test"
+    );
+    mockDeleteLabel(
+      payload.repository.full_name,
+      payload.pull_request.number,
+      "ciflow/1"
+    );
     await probot.receive({ name: "pull_request", id: "123", payload });
   });