Problem: Lpeg requires Lua headers. Currently the include directories
for Lpeg are set only to the bundled deps folder, so if the user wants
to use system Lua/Luajit, Lpeg will not find the system headers and will
fail to build.
Solution: Add system Lua/Luajit include directories when USE_BUNDLED_LUA
and USE_BUNDLED_LUAJIT are turned off.
Fixes#23469
1bf29a0ae1