MediatR >=v9 licensing

Hello,
I'm using the language server protocol library for my own C# language server. Since there hasn't been a published version for a long time, I tried to update by directly adding the library as a submodule and linking to it directly. This caused a problem with the licensing of MediatR, which went commercial since v9:

[Warn  - 1:00:50 PM] LuckyPennySoftware.MediatR.License: You do not have a valid license key for the Lucky Penny software MediatR. This is allowed for development and testing scenarios. If you are running in production you are required to have a licensed version. Please visit https://luckypennysoftware.com to obtain a valid license.

Is there any way to avoid this licensing problem, apart from keeping to an older version of this library (which seems to be https://github.com/OmniSharp/csharp-language-server-protocol/commit/3876e2dea4c4284569ed88effbcc6dae5037a456, shortly after the latest published version )?

Start by comparing the library dependency state with commit 3876e2d and the directly added submodule described in the issue. Review how MediatR is included and whether the project has a documented supported version path; done means the licensing warning is avoided through a maintainer-approved dependency approach.