Merge branch 'revert-to-node-12' into 'main'

chore: revert to node 12

See merge request gitlab-org/gitlab-vscode-extension!302

.gitlab-ci.yml

@@ -15,7 +15,7 @@ default:
   tags:
     - gitlab-org
 
-image: node:14-slim
+image: node:12-slim
 
 stages:
   - test

.tool-versions

-nodejs 14.16.0
+nodejs 12.20.0

tsconfig.json

 {
   "compilerOptions": {
     "module": "commonjs",
-    "target": "es2020",
+    "target": "es6",
     "outDir": "out",
     // we need to include dom library for msw to work, see https://github.com/mswjs/msw/issues/408
-    "lib": ["es2020", "dom"],
+    "lib": ["es6", "dom"],
     "allowJs": true,
     "resolveJsonModule": true,
     "skipLibCheck": true,