refactor: rename LuaState parameter to improve clarity

src/Lua/Runtime/Tracebacks.cs

@@ -121,9 +121,9 @@ public class Traceback(LuaGlobalState globalState, ReadOnlySpan<CallStackFrame>
         return CreateTracebackMessage(GlobalState, StackFrames, LuaValue.Nil, skipFrames);
     }
 
-    public static string CreateTracebackMessage(LuaState thread, LuaValue message, int stackFramesSkipCount = 0)
+    public static string CreateTracebackMessage(LuaState state, LuaValue message, int stackFramesSkipCount = 0)
     {
-        return CreateTracebackMessage(thread.GlobalState, thread.GetCallStackFrames(), message, stackFramesSkipCount);
+        return CreateTracebackMessage(state.GlobalState, state.GetCallStackFrames(), message, stackFramesSkipCount);
     }
 
     internal static string CreateTracebackMessage(LuaGlobalState globalState, ReadOnlySpan<CallStackFrame> stackFrames, LuaValue message, int skipCount = 0)

src/Lua/Runtime/UpValue.cs

@@ -10,14 +10,14 @@ public sealed class UpValue
     public bool IsClosed { get; private set; }
     public int RegisterIndex { get; private set; }
 
-    UpValue(LuaState? thread)
+    UpValue(LuaState? state)
     {
-        Thread = thread;
+        Thread = state;
     }
 
-    public static UpValue Open(LuaState thread, int registerIndex)
+    public static UpValue Open(LuaState state, int registerIndex)
     {
-        return new(thread) { RegisterIndex = registerIndex };
+        return new(state) { RegisterIndex = registerIndex };
     }
 
     public static UpValue Closed(LuaValue value)