Revert "Use pnpm instead of npm" (#1382)

Reverts PhotonVision/photonvision#1375

Causes white screen UI Bug, "the way we currently strap everything with
vue2 and vuetify has a lot of footguns in it, and using a newer package
manager where each subdependency gets its own version of node is causing
incorrect dependency resolution which also means we can't fix this
without either updating node or patching those dependencies id say just
revert the PR for now until I or someone else can do the vue3 update"

.github/workflows/photon-code-docs.yml

@@ -36,20 +36,14 @@ jobs:
     runs-on: ubuntu-22.04
     steps:
       - uses: actions/checkout@v4
-      - name: Install pnpm
-        uses: pnpm/action-setup@v4
-        with:
-          version: 9
       - name: Setup Node.js
         uses: actions/setup-node@v4
         with:
           node-version: 18
-          cache: 'pnpm'
-          cache-dependency-path: '**/pnpm-lock.yaml'
       - name: Install Dependencies
-        run: pnpm install
+        run: npm ci
       - name: Build Production Client
-        run: pnpm run build-demo
+        run: npm run build-demo
       - uses: actions/upload-artifact@v4
         with:
           name: built-client