fix: Use correct stage for adding assets during compilation

src/instances.ts

@@ -313,11 +313,19 @@ function addAssetHooks(loader: WebpackLoaderContext, instance: TSInstance) {
     instance.configFilePath
   );
 
-  const makeAssetsCallback = (compilation: webpack.Compilation) => {
-    compilation.hooks.afterProcessAssets.tap('ts-loader', () =>
-      cachedMakeAfterCompile(compilation, () => {
-        return null;
-      })
+  // compilation is actually of type webpack.Compilation, but afterProcessAssets
+  // only exists in webpack5 and at the time of writing ts-loader is built using webpack4
+  const makeAssetsCallback = (compilation: any) => {
+    compilation.hooks.processAssets.tap(
+      {
+        name: 'ts-loader',
+        stage: webpack.Compilation.PROCESS_ASSETS_STAGE_ADDITIONAL,
+      },
+      (_assets: webpack.Asset[]) => {
+        cachedMakeAfterCompile(compilation, () => {
+          return null;
+        });
+      }
     );
   };