setup.cfg: add Python 3.12 and 3.13 classifiers

Author: generalmimon

setup.cfg

@@ -14,7 +14,7 @@ long_description = file: README.md
 long_description_content_type = text/markdown
 license = MIT
 keywords = kaitai, struct, construct, ksy, declarative, data structure, data format, file format, packet format, binary, parser, parsing, unpack, development
-classifiers = 
+classifiers =
     Development Status :: 4 - Beta
     Intended Audience :: Developers
     Topic :: Software Development :: Build Tools
@@ -30,6 +30,8 @@ classifiers =
     Programming Language :: Python :: 3.9
     Programming Language :: Python :: 3.10
     Programming Language :: Python :: 3.11
+    Programming Language :: Python :: 3.12
+    Programming Language :: Python :: 3.13
     Programming Language :: Python :: Implementation :: CPython
     Programming Language :: Python :: Implementation :: PyPy