Update dependencies from https://github.com/dotnet/arcade build 20210131.1 (#9590)

[master] Update dependencies from dotnet/arcade
- Coherency Updates:
  - XliffTasks: from 1.0.0-beta.21076.1 to 1.0.0-beta.21080.1 (parent: Microsoft.DotNet.Arcade.Sdk)

eng/common/internal-feed-operations.sh

@@ -62,8 +62,6 @@ function SetupCredProvider {
   endpoints+=']'
 
   if [ ${#endpoints} -gt 2 ]; then 
-      # [SuppressMessage("Microsoft.Security", "CS002:SecretInNextLine", Justification="Endpoint code example with no real credentials.")]
-      # Create the JSON object. It should look like '{"endpointCredentials": [{"endpoint":"http://example.index.json", "username":"optional", "password":"accesstoken"}]}'
       local endpointCredentials="{\"endpointCredentials\": "$endpoints"}"
 
       echo "##vso[task.setvariable variable=VSS_NUGET_EXTERNAL_FEED_ENDPOINTS]$endpointCredentials"