Remove most of the `yarn` license warnings

extensions/debug-server-ready/package.json

@@ -4,6 +4,7 @@
 	"description": "%description%",
 	"version": "1.0.0",
 	"publisher": "vscode",
+	"license": "MIT",
 	"engines": {
 		"vscode": "^1.32.0"
 	},

extensions/git-ui/package.json

@@ -3,6 +3,7 @@
   "displayName": "%displayName%",
   "description": "%description%",
   "publisher": "vscode",
+  "license": "MIT",
   "version": "1.0.0",
   "engines": {
     "vscode": "^1.5.0"

extensions/github-authentication/package.json

@@ -3,6 +3,7 @@
   "displayName": "%displayName%",
   "description": "%description%",
   "publisher": "vscode",
+  "license": "MIT",
   "version": "0.0.1",
   "engines": {
     "vscode": "^1.41.0"

extensions/github/package.json

@@ -3,6 +3,7 @@
   "displayName": "%displayName%",
   "description": "%description%",
   "publisher": "vscode",
+  "license": "MIT",
   "version": "0.0.1",
   "engines": {
     "vscode": "^1.41.0"

extensions/microsoft-authentication/package.json

 {
 	"name": "microsoft-authentication",
 	"publisher": "vscode",
+	"license": "MIT",
 	"displayName": "%displayName%",
 	"description": "%description%",
 	"version": "0.0.1",

extensions/package.json

 {
   "name": "vscode-extensions",
   "version": "0.0.1",
+  "license": "MIT",
   "description": "Dependencies shared by all extensions",
   "dependencies": {
     "typescript": "4.1.2"

extensions/vscode-test-resolver/package.json

@@ -3,6 +3,7 @@
 	"description": "Test resolver for VS Code",
 	"version": "0.0.1",
 	"publisher": "vscode",
+	"license": "MIT",
 	"enableProposedApi": true,
 	"private": true,
 	"engines": {

test/integration/browser/package.json

 {
   "name": "code-oss-dev-integration-test",
   "version": "0.1.0",
+  "license": "MIT",
   "main": "./index.js",
   "scripts": {
     "postinstall": "tsc",

test/smoke/package.json

 {
   "name": "code-oss-dev-smoke-test",
   "version": "0.1.0",
+  "license": "MIT",
   "main": "./src/main.js",
   "scripts": {
     "postinstall": "npm run compile",