feat: add @octokit/plugin-retry to handle retriable server errors (#4298)

Add the retry plugin to automatically retry requests that fail with
server errors (5xx status codes). Configure the plugin to exclude 429
(rate limit) from retries since that is already handled by the
throttling plugin.

- Add @octokit/plugin-retry dependency
- Register retry plugin in Octokit client
- Export retryOptions with doNotRetry list excluding 429
- Apply retryOptions in GitHubHelper constructor

src/octokit-client.ts

@@ -2,6 +2,7 @@ import * as core from '@actions/core'
 import {Octokit as OctokitCore} from '@octokit/core'
 import {paginateRest} from '@octokit/plugin-paginate-rest'
 import {restEndpointMethods} from '@octokit/plugin-rest-endpoint-methods'
+import {retry} from '@octokit/plugin-retry'
 import {throttling} from '@octokit/plugin-throttling'
 import {fetch} from 'node-fetch-native/proxy'
 export {RestEndpointMethodTypes} from '@octokit/plugin-rest-endpoint-methods'
@@ -11,6 +12,7 @@ export {OctokitOptions} from '@octokit/core/dist-types/types'
 export const Octokit = OctokitCore.plugin(
   paginateRest,
   restEndpointMethods,
+  retry,
   throttling,
   autoProxyAgent
 )
@@ -32,6 +34,11 @@ export const throttleOptions = {
   }
 }
 
+export const retryOptions = {
+  // 429 is handled by the throttling plugin, so we exclude it from retry
+  doNotRetry: [400, 401, 403, 404, 410, 422, 429, 451]
+}
+
 // Octokit plugin to support the standard environment variables http_proxy, https_proxy and no_proxy
 function autoProxyAgent(octokit: OctokitCore) {
   octokit.hook.before('request', options => {