Add programming language classifiers to fix badge on next publish

Author: VegetarianOrc

pyproject.toml

@@ -14,6 +14,14 @@ dependencies = [
   "types-protobuf>=3.20",
   "typing-extensions>=4.2.0,<5",
 ]
+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 :: 3.14",
+]
 
 [project.optional-dependencies]
 grpc = ["grpcio>=1.48.2,<2"]