Fix docusaurus CI build by switching from yarn to npm

The contrib/docs project uses npm (has package-lock.json, no yarn.lock)
but the workflow was using yarn with cache: yarn. This caused webpack
Progress Plugin validation errors. Switch to npm ci for deterministic
installs matching the lockfile.

Author: skrawcz

.github/workflows/docusaurus-gh-pages.yml

@@ -34,7 +34,6 @@ jobs:
         uses: actions/checkout@v3
         with:
           fetch-depth: 1000
-      # 👇 Build steps
       - name: Set up Python 3.10
         uses: actions/setup-python@v4
         with:
@@ -51,19 +50,14 @@ jobs:
         uses: actions/setup-node@v3
         with:
           node-version: 20.x
-          cache: yarn
-          # The action defaults to search for the dependency file
-          # (package-lock.json or yarn.lock) in the repository root, and uses
-          # its hash as a part of the cache key.
-          # https://github.com/actions/setup-node#caching-packages-dependencies
+          cache: npm
           cache-dependency-path: "./contrib/docs/package-lock.json"
       - name: Install dependencies
         working-directory: contrib/docs
-        run: yarn install --frozen-lockfile --non-interactive
+        run: npm ci
       - name: Build
         working-directory: contrib/docs
-        run: yarn build
-      # 👆 Build steps
+        run: npm run build
   deploy:
     if: ${{ github.ref == 'refs/heads/main' }}
     environment:
@@ -92,19 +86,14 @@ jobs:
         uses: actions/setup-node@v3
         with:
           node-version: 20.x
-          cache: yarn
-          # The action defaults to search for the dependency file
-          # (package-lock.json or yarn.lock) in the repository root, and uses
-          # its hash as a part of the cache key.
-          # https://github.com/actions/setup-node#caching-packages-dependencies
+          cache: npm
           cache-dependency-path: "./contrib/docs/package-lock.json"
       - name: Install dependencies
         working-directory: contrib/docs
-        run: yarn install --frozen-lockfile --non-interactive
+        run: npm ci
       - name: Build
         working-directory: contrib/docs
-        run: yarn build
-      # 👆 Build steps
+        run: npm run build
       - name: Setup Pages
         uses: actions/configure-pages@v3
       - name: Upload artifact