Switch to pnpm

 - needed to add some peer deps that we were missing
 - needed to prevent a compatible upgrade to markdown-link-extractor because it made node-tests hundreds of times slower

.github/actions/setup/action.yml

@@ -0,0 +1,24 @@
+name: Setup node and pnpm
+description: Setup node and install dependencies using pnpm
+inputs:
+  use_lockfile:
+    description: 'Whether to use the lockfile vs latest floating dependencies'
+    required: false
+    default: 'true'
+  use_pinned_node:
+    description: 'Whether to use the node version defined in .npmrc'
+    required: false
+    default: 'false'
+runs:
+  using: 'composite'
+  steps:
+    - uses: pnpm/action-setup@v4
+      name: Install pnpm
+      with:
+        run_install: false
+    - uses: actions/setup-node@v4
+      with:
+        node-version: 20
+        cache: pnpm
+    - run: pnpm install ${{ fromJSON('{"false":"--no-lockfile", "true":"--frozen-lockfile"}')[inputs.use_lockfile] }}
+      shell: bash

.github/workflows/ci.yml

@@ -7,7 +7,6 @@ on:
   pull_request:
 
 env:
-  NODE_VERSION: 20
   NODE_OPTIONS: '--max_old_space_size=4096'
 
 jobs:
@@ -17,17 +16,8 @@ jobs:
     timeout-minutes: 7
     steps:
       - name: Check out a copy of the repo
-        uses: actions/checkout@v3
-
-      - name: Use Node.js ${{ env.NODE_VERSION }}
-        uses: actions/setup-node@v3
-        with:
-          cache: 'npm'
-          node-version: ${{ env.NODE_VERSION }}
-
-      - run: npm i -g npm@9
-      - run: npm ci
-
+        uses: actions/checkout@v4
+      - uses: ./.github/actions/setup
       - name: Lint
         run: npm run lint
 
@@ -37,17 +27,8 @@ jobs:
     timeout-minutes: 7
     steps:
       - name: Check out a copy of the repo
-        uses: actions/checkout@v3
-
-      - name: Use Node.js ${{ env.NODE_VERSION }}
-        uses: actions/setup-node@v3
-        with:
-          cache: 'npm'
-          node-version: ${{ env.NODE_VERSION }}
-
-      - run: npm i -g npm@9
-      - run: npm ci
-
+        uses: actions/checkout@v4
+      - uses: ./.github/actions/setup
       - name: Test
         uses: percy/[email protected]
         with:
@@ -61,16 +42,7 @@ jobs:
     timeout-minutes: 7
     steps:
       - name: Check out a copy of the repo
-        uses: actions/checkout@v2
-
-      - name: Use Node.js ${{ env.NODE_VERSION }}
-        uses: actions/setup-node@v2
-        with:
-          cache: 'npm'
-          node-version: ${{ env.NODE_VERSION }}
-
-      - run: npm i -g npm@9
-      - run: npm ci
-
+        uses: actions/checkout@v4
+      - uses: ./.github/actions/setup
       - name: Test
-        run: npm run test:node
+        run: pnpm run test:node