Update pyproject.toml

Author: baseplate-admin

pyproject.toml

@@ -31,7 +31,6 @@ classifiers = [
     "Operating System :: OS Independent",
     "Programming Language :: Python :: Implementation :: PyPy",
     "Programming Language :: Python",
-    "Programming Language :: Python :: 3.9",
     "Programming Language :: Python :: 3.10",
     "Programming Language :: Python :: 3.11",
     "Programming Language :: Python :: 3.12",