DEV: upgrades dev config (#10588)

.eslintrc

@@ -1,12 +1,6 @@
 {
   "extends": "eslint-config-discourse",
-  "plugins": ["discourse-ember"],
   "rules": {
     "discourse-ember/global-ember": 2
-  },
-  "globals": {
-    "bootbox": "off",
-    "Mousetrap": "off",
-    "_": "off"
   }
 }

.prettierrc

@@ -0,0 +1 @@
+{}

package.json

@@ -14,7 +14,7 @@
     "bootstrap": "v3.4.1",
     "chart.js": "2.9.3",
     "chartjs-plugin-datalabels": "^0.7.0",
-    "eslint-plugin-lodash": "^6.0.0",
+    "eslint-config-discourse": "latest",
     "favcount": "https://github.com/chrishunt/favcount",
     "handlebars": "^4.7.0",
     "highlight.js": "https://github.com/highlightjs/highlight.js",
@@ -43,11 +43,6 @@
     "@arkweid/lefthook": "^0.6.3",
     "chrome-launcher": "^0.12.0",
     "chrome-remote-interface": "^0.25",
-    "ember-template-lint": "^2.5.2",
-    "eslint-config-discourse": "latest",
-    "eslint-plugin-discourse-ember": "latest",
-    "eslint-plugin-ember": "^7.7.1",
-    "eslint-plugin-node": "^10.0.0",
     "lodash-cli": "https://github.com/lodash-archive/lodash-cli.git",
     "pretender": "^1.6",
     "puppeteer": "1.20",