Fix Qt config to target older ES version

Author: brizental

glean/package-lock.json

@@ -90,7 +90,7 @@
     "ts-node": "^9.1.1",
     "typescript": "^4.1.5",
     "web-ext-types": "^3.2.1",
-    "webpack": "^5.21.2",
+    "webpack": "^5.34.0",
     "webpack-cli": "^4.5.0"
   },
   "dependencies": {

glean/package.json

@@ -0,0 +1,7 @@
+{
+  "extends": "./base.json",
+  "compilerOptions": {
+    "target": "ES5"
+  },
+  "include": ["../src/index/qt.ts" ]
+}

glean/tsconfig/qt.json

@@ -33,13 +33,19 @@ class TsResolvePlugin {
 
 export default {
   entry: "./src/index/qt.ts",
+  devtool : "cheap-source-map",
   module: {
     rules: [
       {
         test: /\.tsx?$/,
         loader: "ts-loader",
         exclude: /node_modules/,
-        options: { onlyCompileBundledFiles: true },
+        options: {
+          onlyCompileBundledFiles: true,
+          // This path is resolved relative to the entry file, ./src/index/qt.ts
+          // See: https://github.com/TypeStrong/ts-loader#configfile
+          configFile: "../../tsconfig/qt.json"
+        },
       },
     ],
   },