Migrate to Node 20, clean up workflows (#2902)

Tests still appear to fail per #2898. Unfortunately, I need actions/runner#2347 to ignore the test failures properly - I need them to be warnings, not hard errors.

.github/workflows/pr.yml

@@ -1,38 +0,0 @@
-name: pr
-
-on:
-  push:
-    branches: [ next ]
-
-  workflow_dispatch:
-
-concurrency: prr:pre-release
-
-jobs:
-  pr:
-
-    runs-on: ubuntu-latest
-
-    strategy:
-      matrix:
-        node-version: [16.x]
-
-    steps:
-    - uses: actions/checkout@v3
-    - name: Use Node.js ${{ matrix.node-version }}
-      uses: actions/setup-node@v3
-      with:
-        node-version: ${{ matrix.node-version }}
-        cache: 'npm'
-    - run: npm ci
-    - run: npm run build
-    - run: npx pr-release pr --verbose --target master --source next --compact --verbose --minimize-semver-change
-      env:
-        GITHUB_TOKEN: ${{ secrets.GH_TOKEN }}
-    # The following will publish a prerelease to npm
-    - run: echo "//registry.npmjs.org/:_authToken=$NPM_TOKEN" > ~/.npmrc
-      name: Setup NPM Auth
-      env:
-        NPM_TOKEN: ${{ secrets.NPM_TOKEN }}
-    - run: npx pr-release infer-prerelease --preid=next --target master --source next --verbose --publish --minimize-semver-change
-      name: Publish