Bump Yarn to v4

This allows us to use newer features of Yarn, such as writing
constraints in JavaScript format instead of Prolog.

.yarnrc.yml

@@ -1,6 +1,8 @@
+enableGlobalCache: false
+
 enableScripts: false
 
-enableTelemetry: 0
+enableTelemetry: false
 
 logFilters:
   - code: YN0004
@@ -11,9 +13,3 @@ nodeLinker: node-modules
 plugins:
   - path: .yarn/plugins/@yarnpkg/plugin-allow-scripts.cjs
     spec: "https://raw.githubusercontent.com/LavaMoat/LavaMoat/main/packages/yarn-plugin-allow-scripts/bundles/@yarnpkg/plugin-allow-scripts.js"
-  - path: .yarn/plugins/@yarnpkg/plugin-workspace-tools.cjs
-    spec: "@yarnpkg/plugin-workspace-tools"
-  - path: .yarn/plugins/@yarnpkg/plugin-constraints.cjs
-    spec: "@yarnpkg/plugin-constraints"
-
-yarnPath: .yarn/releases/yarn-3.3.0.cjs

docs/contributing.md

@@ -4,7 +4,7 @@
 
 - Install the current LTS version of [Node.js](https://nodejs.org)
   - If you are using [nvm](https://github.com/creationix/nvm#installation) (recommended) running `nvm install` will install the latest version and running `nvm use` will automatically choose the right node version for you.
-- Install [Yarn v3](https://yarnpkg.com/getting-started/install).
+- [Install Yarn v4 using Corepack](https://yarnpkg.com/getting-started/install).
 - Run `yarn install` to install dependencies and run any required post-install scripts.
 - Run `yarn simple-git-hooks` to add a [Git hook](https://github.com/toplenboren/simple-git-hooks#what-is-a-git-hook) to your local development environment which will ensure that all files pass linting before you push a branch.
 

package.json

@@ -73,7 +73,7 @@
     "typescript": "~4.8.4",
     "which": "^3.0.0"
   },
-  "packageManager": "yarn@3.3.0",
+  "packageManager": "yarn@4.0.2",
   "engines": {
     "node": ">=18.18 || >=20"
   },