add id-token permissions

See /dotnet/docs#40676 for the corresponding PR

.github/workflows/whats-new.yml

@@ -23,6 +23,7 @@ jobs:
  permissions:
  contents: write
  pull-requests: write
+ id-token: write
  if: ${{ github.repository_owner == 'dotnet' }}
 
  # Steps represent a sequence of tasks that will be executed as part of the job