Fix knip configuration for SWC dependencies

Add @swc/core and swc-loader to ignoreDependencies and include swc.config.js
as entry point to prevent knip from marking them as unused.

Fixes lint CI failure.

Author: justin808

knip.ts

@@ -38,6 +38,9 @@ const config: KnipConfig = {
         // This is an optional peer dependency because users without RSC don't need it
         // but Knip doesn't like such dependencies to be referenced directly in code
         'react-on-rails-rsc',
+        // SWC transpiler dependencies used in dummy apps
+        '@swc/core',
+        'swc-loader',
       ],
     },
 
@@ -97,6 +100,8 @@ const config: KnipConfig = {
         'config/webpack/{production,development,test}.js',
         // Declaring this as webpack.config instead doesn't work correctly
         'config/webpack/webpack.config.js',
+        // SWC configuration for Shakapacker
+        'config/swc.config.js',
       ],
       ignore: ['**/app-react16/**/*'],
       project: ['**/*.{js,cjs,mjs,jsx,ts,cts,mts,tsx}!', 'config/webpack/*.js'],