build: migrate from yarn to pnpm as the package manager (#2951)

PR Close #2951

Author: josephperrott

.aspect/rules/external_repository_action_cache/npm_translate_lock_LTkzNjczMzk3Mw==

@@ -1,2 +1 @@
-.yarn/
 node_modules/

.github/ng-renovate/.gitignore

@@ -1,6 +1,5 @@
 {
   "name": "ng-renovate",
-  "packageManager": "[email protected]",
   "type": "commonjs",
   "dependencies": {
     "renovate": "41.58.1"

.github/ng-renovate/.yarnrc.yml

@@ -8,7 +8,7 @@ module.exports = {
   forkModeDisallowMaintainerEdits: true,
   onboarding: false,
   persistRepoData: true,
-  allowedPostUpgradeCommands: ['.', '^yarn install$', '^yarn update-generated-files$'],
+  allowedPostUpgradeCommands: ['.', '^pnpm install$', '^pnpm update-generated-files$'],
   hostRules: [
     {
       matchHost: 'api.github.com',