Create GitHub Action to install zb

.gitattributes

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+/.github/actions/setup-zb/dist/*.js text eol=lf -diff -merge

.github/actions/setup-zb/action.yml

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+name: Set up zb
+description: Install zb
+author: The zb Authors
+inputs:
+  zb-version:
+    description: The zb version to download and use. Be sure to enclose this option in single quotation marks.
+  github-token:
+    description: Personal access token (PAT) used to get zb release information.
+    default: ${{ github.token }}
+runs:
+  using: node24
+  main: dist/main.js

.github/actions/setup-zb/build.mjs

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+/**
+ * @license
+ * Copyright 2026 The zb Authors
+ * SPDX-License-Identifier: MIT
+ */
+
+import { platform } from '@actions/core';
+import * as esbuild from 'esbuild';
+
+await esbuild.build({
+  entryPoints: ['src/main.ts'],
+  bundle: true,
+  minify: false,
+  platform: 'node',
+  target: ['node24.0'],
+  format: 'cjs',
+  outfile: 'dist/main.js',
+});