chore: bump bootstrap pnpm to 11.0.0-beta.4-1 and add update script

Add `pnpm run update-bootstrap [version]` to regenerate the bootstrap
lockfiles. Bumps from 11.0.0-beta.3 to 11.0.0-beta.4-1.

scripts/update-bootstrap.mjs

@@ -0,0 +1,47 @@
+#!/usr/bin/env node
+
+// Usage: node scripts/update-bootstrap.mjs [version]
+// If version is omitted, fetches the latest next-11 tag from npm.
+// Regenerates the bootstrap lockfiles used by action-setup to install pnpm via npm.
+
+import { execSync } from 'child_process'
+import { mkdtempSync, rmSync, readFileSync, writeFileSync } from 'fs'
+import { join } from 'path'
+import { tmpdir } from 'os'
+
+const BOOTSTRAP_DIR = new URL('../src/install-pnpm/bootstrap/', import.meta.url).pathname
+
+const version = process.argv[2] || resolveLatestVersion()
+
+console.log(`Updating bootstrap lockfiles to pnpm@${version} ...`)
+
+generateLock('pnpm-lock.json', { pnpm: version }, 'bootstrap-pnpm')
+generateLock('exe-lock.json', { '@pnpm/exe': version }, 'bootstrap-exe')
+
+console.log('Done!')
+
+function resolveLatestVersion() {
+  const json = execSync('npm view @pnpm/exe dist-tags --json', { encoding: 'utf8' })
+  const tags = JSON.parse(json)
+  const version = tags['next-11'] || tags['latest']
+  if (!version) {
+    console.error('Could not determine latest pnpm version from npm dist-tags')
+    process.exit(1)
+  }
+  return version
+}
+
+function generateLock(filename, dependencies, name) {
+  const tmp = mkdtempSync(join(tmpdir(), 'pnpm-bootstrap-'))
+  try {
+    writeFileSync(join(tmp, 'package.json'), JSON.stringify({ private: true, dependencies }))
+    execSync('npm install --package-lock-only --ignore-scripts', { cwd: tmp, stdio: 'pipe' })
+    const lock = readFileSync(join(tmp, 'package-lock.json'), 'utf8')
+    const parsed = JSON.parse(lock)
+    parsed.name = name
+    writeFileSync(join(BOOTSTRAP_DIR, filename), JSON.stringify(parsed, null, 2) + '\n')
+    console.log(`  ${filename} -> ${Object.values(dependencies)[0]}@${version}`)
+  } finally {
+    rmSync(tmp, { recursive: true, force: true })
+  }
+}