[release/6.x] Update dependencies from dotnet/command-line-api

[dotnet-maestro[bot]]

This pull request updates the following dependencies

From https://github.com/dotnet/command-line-api

• Subscription: 21163daf-3ff9-4df6-007d-08d967f5212f

• Build: 20210923.1

• Date Produced: September 23, 2021 11:23:14 PM UTC

• Commit: 82273cb56c83b589e8e5b63da0ac9745ffc6e105

• Branch: refs/heads/release/dotnet6

• Updates:

  • System.CommandLine: from 2.0.0-beta4.22504.1 to 2.0.0-beta1.21473.1
  • System.CommandLine.Rendering: from 0.4.0-alpha.22504.1 to 0.3.0-alpha.21473.1