update az cli command

Author: sean-breen

.github/actions/az-sync/action.yml

@@ -37,7 +37,7 @@ runs:
             echo "Processing pattern: $pattern"
             for secret_name in $(az keyvault secret list --vault-name ${{ inputs.keyvault }} --query "[?contains(name, '$pattern')].name" -o tsv); do
               echo "Sync secret: env.$secret_name"
-              secret_value=$(az keyvault secret show --name "$secret_name" --vault-name ${{ inputs.keyvault }} --query value -o tsv)
+              secret_value=$(az keyvault secret show --name "$secret_name" --vault-name ${{ inputs.keyvault }} --query value -o tsv 2>/dev/null)
               echo "::add-mask::$secret_value"
               echo "$secret_name=$secret_value" >> $GITHUB_ENV
             done