DEV: Introduce webpack-retry-chunk-load-plugin (#28960)

In our test suite, we sometimes see ChunkLoadErrors. This plugin should cause those failed requests to be retried seamlessly. It'll also help clients with flaky internet connections in production.

app/assets/javascripts/discourse/ember-cli-build.js

@@ -13,6 +13,7 @@ const DeprecationSilencer = require("deprecation-silencer");
 const { compatBuild } = require("@embroider/compat");
 const { Webpack } = require("@embroider/webpack");
 const { StatsWriterPlugin } = require("webpack-stats-plugin");
+const { RetryChunkLoadPlugin } = require("webpack-retry-chunk-load-plugin");
 const withSideWatch = require("./lib/with-side-watch");
 const RawHandlebarsCompiler = require("discourse-hbr/raw-handlebars-compiler");
 const crypto = require("crypto");
@@ -223,6 +224,11 @@ module.exports = function (defaults) {
               return JSON.stringify(output, null, 2);
             },
           }),
+          new RetryChunkLoadPlugin({
+            retryDelay: 200,
+            maxRetries: 2,
+            chunks: ["assets/discourse.js"],
+          }),
         ],
       },
     },

app/assets/javascripts/discourse/package.json

@@ -125,6 +125,7 @@
     "util": "^0.12.5",
     "virtual-dom": "^2.1.1",
     "webpack": "^5.94.0",
+    "webpack-retry-chunk-load-plugin": "^3.1.1",
     "webpack-stats-plugin": "^1.1.3",
     "xss": "^1.0.15"
   },