Add additional metadata to default CIF comment string

Should a bug be found in either pymatgen's CIFWriter or spglib, a key package depended upon by pymatgen, this updated comment string will make it easier to find affected CIF files.

Signed-off-by: Matthew Horton <mkhorton@users.noreply.github.com>

Author: mkhorton

src/pymatgen/io/cif.py

@@ -19,8 +19,9 @@
 from monty.dev import deprecated
 from monty.io import zopen
 from monty.serialization import loadfn
+from spglib import __version__ as __spglib_version__
 
-from pymatgen.core import Composition, DummySpecies, Element, Lattice, PeriodicSite, Species, Structure, get_el_sp
+from pymatgen.core import Composition, DummySpecies, Element, Lattice, PeriodicSite, Species, Structure, get_el_sp, __version__
 from pymatgen.core.operations import MagSymmOp, SymmOp
 from pymatgen.electronic_structure.core import Magmom
 from pymatgen.symmetry.analyzer import SpacegroupAnalyzer, SpacegroupOperations
@@ -254,7 +255,7 @@ def __init__(
         """
         self.data = data
         self.orig_string = orig_string
-        self.comment: str = comment or "# generated using pymatgen"
+        self.comment: str = comment or f"# generated using pymatgen {__version__} (spglib {__spglib_version__})"
 
     def __str__(self) -> str:
         out = "\n".join(map(str, self.data.values()))