Add newer Python versions to trove classifiers

Author: AA-Turner

pyproject.toml

@@ -26,6 +26,12 @@ classifiers = [
     "Operating System :: OS Independent",
     "Programming Language :: Python",
     "Programming Language :: Python :: 3",
+    "Programming Language :: Python :: 3 :: Only",
+    "Programming Language :: Python :: 3.8",
+    "Programming Language :: Python :: 3.9",
+    "Programming Language :: Python :: 3.10",
+    "Programming Language :: Python :: 3.11",
+    "Programming Language :: Python :: 3.12",
     "Framework :: Sphinx",
     "Framework :: Sphinx :: Extension",
     "Topic :: Documentation",