try powershell

Author: gcampbell-msft

build/build.yml

@@ -53,13 +53,13 @@ jobs:
     displayName: Use production AI key
     condition: and(succeeded(), startsWith(variables['Build.SourceBranch'], 'refs/tags'))
   - ${{ if parameters.prerelease }}:
-    - script: |
-        set NODE_OPTIONS="--no-experimental-fetch --openssl-legacy-provider"
+    - pwsh: |
+        $env:NODE_OPTIONS="--no-experimental-fetch --openssl-legacy-provider"
         node build/package.js --pre-release
       displayName: Build and pack extension
   - ${{ else }}:
-    - script: |
-        set NODE_OPTIONS="--no-experimental-fetch --openssl-legacy-provider"
+    - pwsh: |
+        $env:NODE_OPTIONS="--no-experimental-fetch --openssl-legacy-provider"
         node build/package.js
       displayName: Build and pack extension
   - pwsh: |