feat: Adds Python 3.13 support

owlbot.py

@@ -30,6 +30,17 @@
 )
 s.move(templated_files, excludes=["docs/multiprocessing.rst", "README.rst"])
 
+s.replace(
+    ".kokoro/presubmit.cfg",
+    """# Format: //devtools/kokoro/config/proto/build.proto""",
+    """# Format: //devtools/kokoro/config/proto/build.proto
+
+env_vars: {
+    key: "NOX_SESSION"
+    value: "system-3.12 blacken mypy format"
+}""",
+)
+
 python.py_samples(skip_readmes=True)
 
 s.replace(

setup.py

@@ -83,6 +83,7 @@
         "Programming Language :: Python :: 3.10",
         "Programming Language :: Python :: 3.11",
         "Programming Language :: Python :: 3.12",
+        "Programming Language :: Python :: 3.13",
         "Operating System :: OS Independent",
         "Topic :: Internet",
     ],