change <3.13 to <=3.12

Author: Tieqiong

pyproject.toml

@@ -14,7 +14,7 @@ maintainers = [
 description = "Crystal structure container and parsers for structure formats."
 keywords = ['diffpy', 'crystal structure data storage CIF PDB']
 readme = "README.rst"
-requires-python = ">=3.10, < 3.13"
+requires-python = ">=3.10, <=3.12"
 classifiers = [
         'Development Status :: 5 - Production/Stable',
         'Environment :: Console',