NadekoBot.Extensions should now be fully annotated with nullable reference types as well as many classes from NadekoBot.Common

src/NadekoBot/Services/Impl/StartingGuildsListService.cs

@@ -1,4 +1,5 @@
-using System.Collections.Immutable;
+#nullable disable
+using System.Collections.Immutable;
 using System.Collections;
 
 namespace NadekoBot.Services;
@@ -15,4 +16,4 @@ public class StartingGuildsService : IEnumerable<ulong>, INService
 
     IEnumerator IEnumerable.GetEnumerator() =>
         _guilds.GetEnumerator();
-}
+}