DEV: Simplify sprockets configuration (#24111)

- Remove the wildcard crawler. This was already excluding almost all file types, but the exclude list was missing '.gjs' which meant those files were unnecessarily being hoisted into the `public/` directory during precompile

- Automatically include all ember-cli-generated assets without needing them to be listed. The main motivation for this change is to allow us to start using async imports via Embroider/Webpack. The filenames for those new async bundles will not be known in advance.

- Skips sprockets fingerprinting on Embroider/Webpack chunk JS files. Their filenames already include a fingerprint, and having sprockets change the filenames will cause problems for the async import feature (where filenames are included deep inside js bundles)

This commit also updates our ember-cli build so that it skips building plugin tests in the production environment. This should provide a slight build speed improvement.

app/assets/javascripts/discourse-plugins/index.js

@@ -160,14 +160,18 @@ module.exports = {
     });
   },
 
-  generatePluginsTree() {
+  generatePluginsTree(withTests) {
     if (!this.shouldLoadPlugins()) {
       return mergeTrees([]);
     }
-    const appTree = this._generatePluginAppTree();
-    const testTree = this._generatePluginTestTree();
-    const adminTree = this._generatePluginAdminTree();
-    return mergeTrees([appTree, testTree, adminTree]);
+    const trees = [
+      this._generatePluginAppTree(),
+      this._generatePluginAdminTree(),
+    ];
+    if (withTests) {
+      trees.push(this._generatePluginTestTree());
+    }
+    return mergeTrees(trees);
   },
 
   _generatePluginAppTree() {