Update supported language

Since we are pulling the list of Python versions in the README
badge from PyPi we need to ensure we correctly reflect all supported
versions.

Author: dsp-ant

pyproject.toml

@@ -21,6 +21,9 @@ classifiers = [
     "License :: OSI Approved :: MIT License",
     "Programming Language :: Python :: 3",
     "Programming Language :: Python :: 3.10",
+    "Programming Language :: Python :: 3.11",
+    "Programming Language :: Python :: 3.12",
+    "Programming Language :: Python :: 3.13",
 ]
 dependencies = [
     "anyio>=4.6",