.NET March 2023 Update - .NET 6.0.15 and SDK 6.0.115

[dotnet-sb-bot]

Please use the v6.0.115 tag to source-build .NET version 6.0.15 / 6.0.115.

• Release Notes: https://github.com/dotnet/core/blob/main/release-notes/6.0/6.0.15/6.0.115.md
• Tag URL: https://github.com/dotnet/installer/releases/tag/v6.0.115

@dotnet/distro-maintainers

{
  "Channel": "6.0",
  "Runtime": "6.0.15",
  "Sdk": "6.0.115",
  "InstallerTag": "v6.0.115"
}