ci(reviewers): inline scripts, drop checkout #40413

Problem:
- The `reviewers_add`/`reviewers_remove` CI jobs checkout the repo only
  for the purpose of `require('…/reviewers_add.js')`.
- `reviewers_remove` also runs on `closed`, so a merged fork PR will trip
  the new allow-unsafe-pr-checkout guard of `actions/checkout@v7`.

Solution:
- Drop the use of `actions/checkout`.
- Inline the script in the CI yaml definitions.
- Also await the mutating calls (previously fire-and-forget) and guard
  empty reviewer lists.

.github/scripts/reviewers_add.js

@@ -1,118 +0,0 @@
-module.exports = async ({ github, context }) => {
-  const pr_data = await github.rest.pulls.get({
-    owner: context.repo.owner,
-    repo: context.repo.repo,
-    pull_number: context.issue.number,
-  });
-  const labels = pr_data.data.labels.map((e) => e.name);
-  const reviewers = new Set();
-
-  if (labels.includes("build")) {
-    reviewers.add("dundargoc");
-    reviewers.add("jamessan");
-    reviewers.add("justinmk");
-  }
-
-  if (labels.includes("ci")) {
-    reviewers.add("dundargoc");
-    reviewers.add("jamessan");
-    reviewers.add("justinmk");
-  }
-
-  if (labels.includes("column")) {
-    reviewers.add("lewis6991");
-  }
-
-  if (labels.includes("comment")) {
-    reviewers.add("echasnovski");
-  }
-
-  if (labels.includes("defaults")) {
-    reviewers.add("gpanders");
-  }
-
-  if (labels.includes("diagnostic")) {
-    reviewers.add("gpanders");
-  }
-
-  if (labels.includes("diff")) {
-    reviewers.add("lewis6991");
-  }
-
-  if (labels.includes("editorconfig")) {
-    reviewers.add("gpanders");
-  }
-
-  if (labels.includes("marks")) {
-    reviewers.add("bfredl");
-  }
-
-  if (labels.includes("filetype")) {
-    reviewers.add("clason");
-  }
-
-  if (labels.includes("inccommand")) {
-    reviewers.add("famiu");
-  }
-
-  if (labels.includes("lsp")) {
-    reviewers.add("MariaSolOs");
-    reviewers.add("ribru17");
-  }
-
-  if (labels.includes("netrw")) {
-    reviewers.add("justinmk");
-  }
-
-  if (labels.includes("options")) {
-    reviewers.add("famiu");
-  }
-
-  if (labels.includes("platform:nix")) {
-    reviewers.add("teto");
-  }
-
-  if (labels.includes("project-management")) {
-    reviewers.add("bfredl");
-    reviewers.add("justinmk");
-  }
-
-  if (labels.includes("snippet")) {
-    reviewers.add("MariaSolOs");
-  }
-
-  if (labels.includes("statusline")) {
-    reviewers.add("famiu");
-  }
-
-  if (labels.includes("treesitter")) {
-    reviewers.add("bfredl");
-    reviewers.add("clason");
-    reviewers.add("lewis6991");
-    reviewers.add("wookayin");
-    reviewers.add("ribru17");
-  }
-
-  if (labels.includes("tui")) {
-    reviewers.add("gpanders");
-  }
-
-  if (labels.includes("typo")) {
-    reviewers.add("dundargoc");
-  }
-
-  if (labels.includes("vim-patch")) {
-    reviewers.add("zeertzjq");
-  }
-
-  // Remove person that opened the PR since they can't review themselves
-  const pr_opener = pr_data.data.user.login;
-  reviewers.delete(pr_opener);
-
-  github.rest.pulls.requestReviewers({
-    owner: context.repo.owner,
-    repo: context.repo.repo,
-    pull_number: context.issue.number,
-    reviewers: Array.from(reviewers),
-  });
-};

.github/scripts/reviewers_remove.js

@@ -1,16 +0,0 @@
-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,
-  });
-};