Fix eslint setup

babel-eslint isn't working with node 16 anymore

In addition to the new packages, also turn the remaining Ember errors
into warnings, so we can fix them without `npm test` failing in the
meantime.

package.json

@@ -26,10 +26,11 @@
     "deploy": "git push 5apps master"
   },
   "devDependencies": {
+    "@babel/eslint-parser": "^7.19.1",
+    "@babel/plugin-proposal-decorators": "^7.19.3",
     "@ember/optional-features": "^1.3.0",
     "@glimmer/component": "^1.0.0",
     "@glimmer/tracking": "^1.0.0",
-    "babel-eslint": "^10.1.0",
     "babel-preset-es2015": "^6.22.0",
     "broccoli-asset-rev": "^3.0.0",
     "ember-auto-import": "^1.12.1",
@@ -61,7 +62,7 @@
     "ember-template-lint": "^2.8.0",
     "ember-truth-helpers": "^3.0.0",
     "eslint": "^8.14.0",
-    "eslint-plugin-ember": "^10.6.0",
+    "eslint-plugin-ember": "^11.0.6",
     "eslint-plugin-node": "^11.1.0",
     "ethers": "^5.4.7",
     "fetch-mock": "^9.10.7",