Breaking change: Remove deprecated GetDebugString() from protobuf python cpp extension.

cpp extension added the API in https://github.com/protocolbuffers/protobuf/pull/7498
Pure python and upb do not support it and filtered out the test
This API does not exists in any other language except C++.

PiperOrigin-RevId: 691870623

python/google/protobuf/internal/descriptor_test.py

@@ -236,13 +236,6 @@ class DescriptorTest(unittest.TestCase):
   def testContainingServiceFixups(self):
     self.assertEqual(self.my_service, self.my_method.containing_service)
 
-  @unittest.skipIf(
-      api_implementation.Type() == 'python',
-      'GetDebugString is only available with the cpp implementation',
-  )
-  def testGetDebugString(self):
-    self.assertEqual(self.my_file.GetDebugString(), TEST_FILE_DESCRIPTOR_DEBUG)
-
   def testGetOptions(self):
     self.assertEqual(self.my_enum.GetOptions(),
                      descriptor_pb2.EnumOptions())

python/google/protobuf/pyext/descriptor.cc

@@ -1512,15 +1512,6 @@ static int SetHasOptions(PyFileDescriptor *self, PyObject *value,
   return CheckCalledFromGeneratedFile("has_options");
 }
 
-static PyObject* GetDebugString(PyFileDescriptor* self) {
-  PyErr_Warn(nullptr,
-             "GetDebugString() API is deprecated. This API only "
-             "exists in protobuf c++ and does not exists in pure python, upb "
-             "or any other languages. GetDebugString() for python cpp "
-             "extension will be removed in Jan 2025");
-  return PyString_FromCppString(_GetDescriptor(self)->DebugString());
-}
-
 static PyObject* GetOptions(PyFileDescriptor *self) {
   return GetOrBuildOptions(_GetDescriptor(self));
 }
@@ -1569,7 +1560,6 @@ static PyGetSetDef Getters[] = {
 };
 
 static PyMethodDef Methods[] = {
-    {"GetDebugString", (PyCFunction)GetDebugString, METH_NOARGS},
     {"GetOptions", (PyCFunction)GetOptions, METH_NOARGS},
     {"_GetFeatures", (PyCFunction)GetFeatures, METH_NOARGS},
     {"CopyToProto", (PyCFunction)CopyToProto, METH_O},

python/pb_unit_tests/descriptor_test_wrapper.py

@@ -35,7 +35,5 @@ import unittest
 # Our error message is better.
 NewDescriptorTest.testImmutableCppDescriptor.__unittest_expecting_failure__ = True
 
-DescriptorTest.testGetDebugString.__unittest_expecting_failure__ = True
-
 if __name__ == '__main__':
   unittest.main(verbosity=2)