ci: Remove old vendoring solution in favor of relying on yarn-path (#35083)

Now that bazel respects the yarn-path value found in .yarnrc, we can
remove the last remaining reliances on our vendoring in
//third_party/github.com/yarnpkg/yarn/

PR Close #35083

.circleci/config.yml

@@ -120,25 +120,11 @@ commands:
       - attach_workspace:
           at: *workspace_location
 
-  # Overwrite the yarn installed in the docker container with our own version.
-  overwrite_yarn:
-    description: Overwrite yarn with our own version
-    steps:
-      - run:
-          name: Overwrite yarn
-          command: |
-            localYarnPath=`node ./.circleci/get-vendored-yarn-path.js`
-            sudo chmod a+x $localYarnPath
-            sudo ln -fs $localYarnPath /usr/local/bin/yarn
-      - run: node --version
-      - run: yarn --version
-
   # Initializes the CI environment by setting up common environment variables.
   init_environment:
-    description: Initializing environment (setting up variables, overwriting Yarn)
+    description: Initializing environment (setting up variables)
     steps:
       - run: ./.circleci/env.sh
-      - overwrite_yarn
       - run:
           # Configure git as the CircleCI `checkout` command does.
           # This is needed because we only checkout on the setup job.
@@ -160,10 +146,6 @@ commands:
       - custom_attach_workspace
       # Install Bazel pre-requisites that aren't in the preconfigured CircleCI Windows VM.
       - run: ./.circleci/windows-env.ps1
-      - run:
-          # Overwrite the yarn installed in the docker container with our own version.
-          name: Overwrite yarn with our own version
-          command: ./.circleci/windows-yarn-setup.ps1
       - run: node --version
       - run: yarn --version
       - restore_cache:
@@ -621,10 +603,8 @@ jobs:
           command: |
             git fetch origin $CI_STABLE_BRANCH
             git checkout --force origin/$CI_STABLE_BRANCH -- aio/ .yarn/ .yarnrc
-        # Overwrite yarn again to use the version from the checked out branch.
-      - overwrite_yarn
-        # Ignore yarn's engines check, because we checked out `aio/package.json` from the stable
-        # branch and there could be a node version skew, which is acceptable in this monitoring job.
+      # Ignore yarn's engines check, because we checked out `aio/package.json` from the stable
+      # branch and there could be a node version skew, which is acceptable in this monitoring job.
       - run: yarn config set ignore-engines true
       - run:
           name: Run tests against https://angular.io/

.circleci/get-vendored-yarn-path.js

@@ -1,36 +0,0 @@
-#!/usr/bin/env node
-'use strict';
-
-/**
- * **Usage:**
- * ```
- * node get-vendored-yarn-path
- * ```
- *
- * Returns the path to the vendored `yarn.js` script, so that it can be used for setting up yarn
- * aliases/symlinks and use the local, vendored yarn script instead of a globally installed one.
- *
- * **Context:**
- * We keep a version of yarn in the repo, at `third_party/github.com/yarnpkg/`. All CI jobs should
- * use that version for consistency (and easier updates). The path to the actual `yarn.js` script,
- * however, changes depending on the version (e.g. `third_party/github.com/yarnpkg/v1.21.1/...`).
- *
- * This script infers the correct path, so that we don't have to update the path in several places,
- * when we update the version of yarn in `third_party/github.com/yarnpkg/`.
- */
-
-const {readdirSync} = require('fs');
-const {normalize} = require('path');
-
-const yarnDownloadDir = `${__dirname}/../third_party/github.com/yarnpkg/yarn/releases/download`;
-const yarnVersionSubdirs = readdirSync(yarnDownloadDir);
-
-// Based on our current process, there should be exactly one sub-directory inside
-// `vendoredYarnDownloadDir` at all times. Throw, if that is not the case.
-if (yarnVersionSubdirs.length !== 1) {
-  throw new Error(
-      `Expected exactly 1 yarn version in '${yarnDownloadDir}', but found ` +
-      `${yarnVersionSubdirs.length}: ${yarnVersionSubdirs.join(', ')}`);
-}
-
-console.log(normalize(`${yarnDownloadDir}/${yarnVersionSubdirs[0]}/bin/yarn.js`));

.circleci/windows-yarn-setup.ps1

@@ -1,14 +0,0 @@
-# Use our local, vendored yarn in the global `yarn` command.
-$globalYarnDir = "$HOME\AppData\Roaming\yarn"
-$localYarnPath = & ${Env:ProgramFiles}\nodejs\node.exe ".\.circleci\get-vendored-yarn-path.js"
-
-# Create a directory to put the yarn PowerShell script.
-New-Item -Path "$globalYarnDir" -ItemType "directory" >$null
-
-# Create the yarn PowerShell script (using the inferred path to the local yarn script).
-Get-Content -Path ".\.circleci\windows-yarn.ps1.template" |
-  %{$_ -replace "{{ LOCAL_YARN_PATH_PLACEHOLDER }}", "$localYarnPath"} |
-  Add-Content -Path "$globalYarnDir\yarn.ps1"
-
-# Add the directory containing the yarn PowerShell script to `PATH`.
-Add-Content -Path $profile -Value ('$Env:path = "{0};" + $Env:path' -f $globalYarnDir)

.circleci/windows-yarn.ps1.template

@@ -1,15 +0,0 @@
-$exe=""
-if ($PSVersionTable.PSVersion -lt "6.0" -or $IsWindows) {
-  # Fix case when both the Windows and Linux builds of Node
-  # are installed in the same directory
-  $exe=".exe"
-}
-$ret=0
-if (Test-Path "$basedir/node$exe") {
-  & "$basedir/node$exe"  "{{ LOCAL_YARN_PATH_PLACEHOLDER }}" $args
-  $ret=$LASTEXITCODE
-} else {
-  & "node$exe"  "{{ LOCAL_YARN_PATH_PLACEHOLDER }}" $args
-  $ret=$LASTEXITCODE
-}
-exit $ret