ci: remove reviewers when drafting or closing a PR

.github/scripts/remove-reviewers.js

@@ -0,0 +1,16 @@
+module.exports = async ({github, context}) => {
+  const requestedReviewers = await github.rest.pulls.listRequestedReviewers({
+    owner: context.repo.owner,
+    repo: context.repo.repo,
+    pull_number: context.issue.number
+  });
+
+  const reviewers = requestedReviewers.data.users.map(e => e.login)
+
+  github.rest.pulls.removeRequestedReviewers({
+    owner: context.repo.owner,
+    repo: context.repo.repo,
+    pull_number: context.issue.number,
+    reviewers: reviewers
+  });
+}

.github/workflows/remove-reviewers-on-draft.yml

@@ -0,0 +1,17 @@
+name: "Remove reviewers"
+on:
+  pull_request_target:
+    types: [converted_to_draft, closed]
+jobs:
+  remove-reviewers:
+    runs-on: ubuntu-latest
+    permissions:
+      pull-requests: write
+    steps:
+      - uses: actions/checkout@v2
+      - name: 'Remove reviewers'
+        uses: actions/github-script@v6
+        with:
+          script: |
+            const script = require('./.github/scripts/remove-reviewers.js')
+            await script({github, context})