Build tweaks (#255857)

* Revert "remove unnecessary build step (#255764)"

This reverts commit 50bf321791.

* Add `enableCrossOsArchive: true`

.github/workflows/pr-node-modules.yml

@@ -72,6 +72,7 @@ jobs:
         id: cache-builtin-extensions
         uses: actions/cache@v4
         with:
+          enableCrossOsArchive: true
           path: .build/builtInExtensions
           key: "builtin-extensions-${{ hashFiles('.build/builtindepshash') }}"
 
@@ -108,6 +109,23 @@ jobs:
           path: .build/node_modules_cache
           key: "node_modules-linux-${{ hashFiles('.build/packagelockhash') }}"
 
+      - name: Install build dependencies
+        if: steps.cache-node-modules.outputs.cache-hit != 'true'
+        working-directory: build
+        run: |
+          set -e
+
+          for i in {1..5}; do # try 5 times
+            npm ci && break
+            if [ $i -eq 5 ]; then
+              echo "Npm install failed too many times" >&2
+              exit 1
+            fi
+            echo "Npm install failed $i, trying again..."
+          done
+        env:
+          GITHUB_TOKEN: ${{ secrets.VSCODE_OSS }}
+
       - name: Install dependencies
         if: steps.cache-node-modules.outputs.cache-hit != 'true'
         run: |