How can I prevent repositories.config from being automatically added to TFS?

Question

I am using NuGet v2.8.60610.756. Every time I build a solution in VS2013, packages/repositories.config is automatically added to source control (TFVC) as a pending change. How can I prevent this?

I have added a .tfignore file at the solution root with the following entries, but it does not make a difference.

## Ignore the NuGet packages folder in the root of the repository
packages
packages/*

I have also set disableSourceControlIntegration to true in .nuget/NuGet.config

<configuration>
  <solution>
    <add key="disableSourceControlIntegration" value="true" />
  </solution>
</configuration>