refactor(cell): remove unused cross-module includes in read_atoms.cpp

Drop two dead includes that create needless reverse dependencies from
source_cell onto higher layers:
  - source_estate/read_orb.h  (elecstate::read_orb_file not used here;
    the real user is read_atoms_helper.cpp)
  - source_basis/module_ao/ORB_read.h  (ORB / LCAO_Orbitals not used here)

Verified by compiling the `cell` target with ENABLE_LCAO=ON so the
former `#ifdef __LCAO` block was actually exercised.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: Critsium-xy

source/source_cell/read_atoms.cpp

@@ -8,16 +8,11 @@
 #include "source_io/module_parameter/parameter.h"
 #include "print_cell.h"
 #include "read_stru.h"
-#include "source_estate/read_orb.h"
 #include "source_base/timer.h"
 #include "source_base/constants.h"
 #include "source_base/formatter.h"
 #include "source_base/mathzone.h"
 
-#ifdef __LCAO
-#include "source_basis/module_ao/ORB_read.h" // to use 'ORB' -- mohan 2021-01-30
-#endif
-
 bool unitcell::read_atom_positions(UnitCell& ucell,
                          std::ifstream &ifpos,
                          std::ofstream &ofs_running,