Make release-3.9 buildable

With this change, you can build the branch using `npm ci && npm run
build`.

Author: amcasey

.github/workflows/ci.yml

@@ -32,10 +32,8 @@ jobs:
         npm uninstall tslint --no-save
     - name: npm install and test
       run: |
-        npm install
-        npm update
+        npm ci
         npm test
-        
+
     - name: Validate the browser can import TypeScript
       run: gulp test-browser-integration
-    

.gitignore

@@ -84,7 +84,6 @@ tests/cases/user/*/**/*.d.ts
 tests/baselines/reference/dt
 .failed-tests
 TEST-results.xml
-package-lock.json
 tests/cases/user/TypeScript-React-Starter/TypeScript-React-Starter
 tests/cases/user/TypeScript-Node-Starter/TypeScript-Node-Starter
 tests/cases/user/TypeScript-React-Native-Starter/TypeScript-React-Native-Starter

.npmrc

@@ -1,7 +1,8 @@
 language: node_js
 
 node_js:
-  - 'node'
+  - '14'
+  - '12'
   - '10'
   - '8'
 
@@ -18,7 +19,7 @@ branches:
 
 install:
   - npm uninstall typescript --no-save
-  - npm install
+  - npm ci
 
 cache:
   directories: