[Tests] test on v4 of the TS parser

Pinned to v4.0 pending typescript-eslint/typescript-eslint#3788

Author: ljharb

.github/workflows/node-4+.yml

@@ -74,7 +74,7 @@ jobs:
         name: 'nvm install ${{ matrix.node-version }} && npm install'
         with:
           node-version: ${{ matrix.node-version }}
-          after_install: npm install --no-save "eslint@${{ matrix.eslint }}" "@typescript-eslint/parser@${{ matrix.node-version >= 10 && '3' || '2' }}" "babel-eslint@${{ matrix.babel-eslint }}"
+          after_install: npm install --no-save "eslint@${{ matrix.eslint }}" "@typescript-eslint/parser@${{ matrix.node-version >= 10 && '4.0' || (matrix.node-version >= 8 && '3' || '2') }}" "babel-eslint@${{ matrix.babel-eslint }}"
           skip-ls-check: true
         env:
           NPM_CONFIG_LEGACY_PEER_DEPS: true

package.json

@@ -46,7 +46,7 @@
     "@types/eslint": "=7.2.10",
     "@types/estree": "^0.0.47",
     "@types/node": "^14.14.37",
-    "@typescript-eslint/parser": "^2.34.0 || ^3.10.1",
+    "@typescript-eslint/parser": "^2.34.0 || ^3.10.1 || ~4.0",
     "aud": "^1.1.5",
     "babel-eslint": "^8 || ^9 || ^10.1.0",
     "eslint": "^3 || ^4 || ^5 || ^6 || ^7",