I was able to resolve this issue by clearing the NuGet cache and restarting Visual Studio.

Here’s what I did:

1. In Visual Studio, I went to
   Tools → Options → NuGet Package Manager → General
   and clicked on "Clear All NuGet Cache(s)".

2. Then I restarted Visual Studio.

After doing this, the error disappeared and I was able to publish my project successfully. I can't believe I forgot to try that earlier.

Thanks to the user who suggested this solution on GitHub!