build: move cleanupNodeModules to its own file

this is necessary, since for Docker and electron-forge, we need to run this as an extra step after copy-dist

for electron-forge: after it is done with its own "pruning", as we otherwise would need to also take care of certain electron related pruning

for Docker: as a last step in the build stage

forge.config.cjs

@@ -1,5 +1,6 @@
 const path = require("path");
 const fs = require("fs-extra");
+const { execSync } = require("child_process");
 
 const APP_NAME = "TriliumNext Notes";
 const BIN_PATH = path.normalize("./bin/electron-forge");
@@ -18,8 +19,6 @@ module.exports = {
     // we run electron-forge inside the ./build folder,
     // to have it output to ./dist, we need to go up a directory first
     outDir: "../dist",
-    // we prune ourselves via copy-dist
-    prune: false,
     packagerConfig: {
         executableName: "trilium",
         name: APP_NAME,
@@ -41,6 +40,22 @@ module.exports = {
             "translations/",
             "node_modules/@highlightjs/cdn-assets/styles"
         ],
+        afterPrune: [
+            (buildPath, _electronVersion, _platform, _arch, callback) => {
+                // buildPath is a temporary directory that electron-packager creates - it's in the form of
+                // /tmp/electron-packager/tmp-SjJl0s/resources/app
+                try {
+                    const cleanupNodeModulesScript = path.join(buildPath, "bin", "cleanupNodeModules.ts");
+                    // we don't have access to any devDeps like 'tsx' here, so use the built-in '--experimental-strip-types' flag instead
+                    const command = `node --experimental-strip-types ${cleanupNodeModulesScript} '${buildPath}'`;
+                    // execSync throws, if above returns any non-zero exit code
+                    execSync(command);
+                    callback()
+                } catch(err) {
+                    callback(err)
+                }
+            }
+        ],
         afterComplete: [
             (buildPath, _electronVersion, platform, _arch, callback) => {
                 // Only move resources on non-macOS platforms