ci: use correct version of pnpm + node 20

turns out [this is optional](https://github.com/pnpm/action-setup/tree/master#version) if `packageManager` is set in `package.json` (which it is). I imagine the version mismatch was the cause of our woes

.github/workflows/docs.yml

@@ -12,9 +12,7 @@ jobs:
         uses: actions/checkout@v3
         with:
           submodules: recursive
-      - uses: pnpm/[email protected]
-        with:
-          version: 7
+      - uses: pnpm/[email protected]
       - name: Use Node.js 18
         uses: actions/setup-node@v3
         with:

.github/workflows/lint.yml

@@ -11,16 +11,14 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        node-version: [16.x, 18.x]
+        node-version: [16.x, 18.x, 20.x]
 
     steps:
       - name: Checkout repository and submodules
         uses: actions/checkout@v3
         with:
           submodules: recursive
-      - uses: pnpm/[email protected]
-        with:
-          version: 7
+      - uses: pnpm/[email protected]
       - name: Use Node.js ${{ matrix.node-version }}
         uses: actions/setup-node@v3
         with: