Bump Yarn 1.22.22 -> 4.9.4 - Remove sha1 hashes (#1555)

* Bump yarn JS package manager 1.22.22 to 4.9.4

This removes sha1 hashes from yarn.lock. Compliant with microsoft hashing.

This adds the yarn berry config / package files: .yarn/ project-local workspace and .yarnrc.yml berry config

Here we bootstrap yarnin devcontainer postCreate

* Update test-project to yarn 4.9.4 and eexplicitly write packageManager 4.9.4

---------

Co-authored-by: devcontainers-bot <devcontainers+bot@example.com>

Author: sam-byng

.devcontainer/devcontainer.json

@@ -4,7 +4,7 @@
         "ghcr.io/devcontainers/features/docker-in-docker:2": {},
         "ghcr.io/devcontainers/features/azure-cli:1": {}
     },
-    "postCreateCommand": "npm install -g @devcontainers/cli",
+    "postCreateCommand": "corepack enable && corepack prepare yarn@4.9.4 --activate && npm install -g @devcontainers/cli",
     "customizations": {
         "vscode": {
             "extensions": [

.yarn/install-state.gz

@@ -0,0 +1 @@
+nodeLinker: node-modules

.yarnrc.yml

@@ -1,12 +1,13 @@
 {
   "files": [
-		"src"
-	],
-	"devDependencies": {
-		"mkdirp": "0.5.5",
-		"copyfiles": "^2.4.1",
-		"handlebars": "^4.7.7",
-		"jsonc": "^2.0.0",
-		"rimraf": "^3.0.2"
-	}
-}
+    "src"
+  ],
+  "devDependencies": {
+    "copyfiles": "^2.4.1",
+    "handlebars": "^4.7.7",
+    "jsonc": "^2.0.0",
+    "mkdirp": "0.5.5",
+    "rimraf": "^3.0.2"
+  },
+  "packageManager": "yarn@4.9.4"
+}

package.json

@@ -1,5 +1,6 @@
 {
   "dependencies": {
     "puppeteer": "^5.5.0"
-  }
+  },
+  "packageManager": "yarn@4.9.4"
 }