update actual pipeline with working directory changes

Author: aishwaryabh

eng/ci/templates/official/jobs/build-test.yml

@@ -82,9 +82,11 @@ jobs:
       .\validateWorkerVersions.ps1
     displayName: 'Validate worker versions'
     condition: ne(variables['skipWorkerVersionValidation'], 'true')
-  - pwsh: |
-      .\check-vulnerabilities.ps1
-    displayName: "Check for security vulnerabilities"
+  - task: PowerShell@2
+    displayName: "Run Check Vulnerabilities Script"
+    inputs:
+      filePath: '$(Build.SourcesDirectory)/check-vulnerabilities.ps1'
+      workingDirectory: '$(Build.SourcesDirectory)/src/Azure.Functions.Cli'
   - pwsh: |
       .\build.ps1
     env: