fix: add mcpplibs-capi-lua to test for module resolution

The installed loader/executor cppm files import mcpplibs.capi.lua,
so the test target needs explicit access to that module for scanning.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: Sunrisepeak

tests/m/mcpplibs-xpkg/xmake.lua

@@ -1,8 +1,9 @@
 add_requires("mcpplibs-xpkg 0.0.1")
+add_requires("mcpplibs-capi-lua 0.0.1")
 
 target("mcpplibs-xpkg_test")
     set_kind("binary")
     set_languages("c++23")
     add_files("main.cpp")
-    add_packages("mcpplibs-xpkg")
+    add_packages("mcpplibs-xpkg", "mcpplibs-capi-lua")
     set_policy("build.c++.modules", true)