feat: Add support for Python 3.13

.github/sync-repo-settings.yaml

@@ -23,8 +23,10 @@ branchProtectionRules:
     - 'unit (3.11, upb)'
     - 'unit (3.12, python)'
     - 'unit (3.12, upb)'
-    - 'prerelease (3.12, python)'
-    - 'prerelease (3.12, upb)'
+    - 'unit (3.13, python)'
+    - 'unit (3.13, upb)'
+    - 'prerelease (3.13, python)'
+    - 'prerelease (3.13, upb)'
     - cover
     - OwlBot Post Processor
     - 'cla/google'

.github/workflows/tests.yml

@@ -87,7 +87,7 @@ jobs:
     runs-on: ubuntu-22.04
     strategy:
       matrix:
-        python: ['3.12']
+        python: ['3.13']
         variant: ['python', 'upb']
     steps:
       - uses: actions/checkout@v4

noxfile.py

@@ -77,7 +77,7 @@ def unit(session, implementation):
 # Only test upb and python implementation backends.
 # As of protobuf 4.x, the "ccp" implementation is not available in the PyPI package as per
 # https://github.com/protocolbuffers/protobuf/tree/main/python#implementation-backends
-@nox.session(python=PYTHON_VERSIONS[-2])
+@nox.session(python=PYTHON_VERSIONS[-1])
 @nox.parametrize("implementation", ["python", "upb"])
 def prerelease_deps(session, implementation):
     """Run the unit test suite against pre-release versions of dependencies."""

setup.py

@@ -62,6 +62,7 @@
         "Programming Language :: Python :: 3.10",
         "Programming Language :: Python :: 3.11",
         "Programming Language :: Python :: 3.12",
+        "Programming Language :: Python :: 3.13",
         "Topic :: Software Development :: Code Generators",
         "Topic :: Software Development :: Libraries :: Python Modules",
     ],