fix!: require NODE_USE_ENV_PROXY for proxy support (#342)

BREAKING CHANGE: Custom proxy handling has been removed. If you use HTTP_PROXY or HTTPS_PROXY, you must now also set NODE_USE_ENV_PROXY=1 on the action step.

lib/request.js

@@ -4,6 +4,31 @@ import { request } from "@octokit/request";
 // Get the GitHub API URL from the action input and remove any trailing slash
 const baseUrl = core.getInput("github-api-url").replace(/\/$/, "");
 
+const proxyEnvironmentKeys = [
+  "https_proxy",
+  "HTTPS_PROXY",
+  "http_proxy",
+  "HTTP_PROXY",
+];
+
+function proxyEnvironmentConfigured() {
+  return proxyEnvironmentKeys.some((key) => process.env[key]);
+}
+
+function nativeProxySupportEnabled() {
+  return process.env.NODE_USE_ENV_PROXY === "1";
+}
+
+export function ensureNativeProxySupport() {
+  if (!proxyEnvironmentConfigured() || nativeProxySupportEnabled()) {
+    return;
+  }
+
+  throw new Error(
+    "A proxy environment variable is set, but Node.js native proxy support is not enabled. Set NODE_USE_ENV_PROXY=1 for this action step.",
+  );
+}
+
 // Configure the default settings for GitHub API requests
 export default request.defaults({
   headers: { "user-agent": "actions/create-github-app-token" },