refactor: remove greeter classes

src/StevanFreeborn.Atproto.IdentityResolver/Greeter.cs

@@ -1,9 +0,0 @@
-namespace StevanFreeborn.Atproto.IdentityResolver;
-
-internal class Greeter
-{
-  public static string SayHello()
-  {
-    return "Hi!";
-  }
-}

tests/StevanFreeborn.Atproto.IdentityResolver.Tests/GreeterTests.cs

@@ -1,10 +0,0 @@
-namespace StevanFreeborn.Atproto.IdentityResolver.Tests;
-
-public class GreeterTests
-{
-  [Fact]
-  public void SayHello_WhenCalled_ItShouldReturnHi()
-  {
-    Greeter.SayHello().Should().Be("Hi!");
-  }
-}