hotfix: the lua-src fork ships, and the build resolves again

- the workspace pointed at third_party/lua-src (the Lua 5.1 fork the addon VM builds on) and the export left that folder behind — every build of today's snapshots broke at dependency resolution
- third_party/ now ships, and the sync gained a gate that refuses to publish an export that does not resolve as a cargo workspace

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

third_party/lua-src/lua-5.1.5/lapi.h

@@ -0,0 +1,16 @@
+/*
+** $Id: lapi.h,v 2.2.1.1 2007/12/27 13:02:25 roberto Exp $
+** Auxiliary functions from Lua API
+** See Copyright Notice in lua.h
+*/
+
+#ifndef lapi_h
+#define lapi_h
+
+
+#include "lobject.h"
+
+
+LUAI_FUNC void luaA_pushobject (lua_State *L, const TValue *o);
+
+#endif