Add classifiers.

And appease python-check-versions, as I don't want to increase `requires_python` at this moment.

Author: mauritsvanrees

.meta.toml

@@ -14,3 +14,9 @@ test_extras = """
     tests
 """
 test_matrix = { "6.0" = ["*"] }
+envlist_lines = """
+# Add envs to prevent python-check-versions to complain,
+# which would force us to set requires_python to 3.9+,
+# which I don't want to do in a bugfix release.
+    py38-plone60
+"""

setup.py

@@ -27,6 +27,8 @@
         "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",
         "Topic :: Software Development :: Libraries :: Python Modules",
     ],
     keywords="plone schema field",

tox.ini

@@ -13,6 +13,10 @@ envlist =
     py310-plone60
     py39-plone60
     dependencies
+# Add envs to prevent python-check-versions to complain,
+# which would force us to set requires_python to 3.9+,
+# which I don't want to do in a bugfix release.
+    py38-plone60
 
 
 ##