Python class generated by protoc cannot be imported in the code because of unresolved references (Mac OS)

I tried to use protocol buffers on my project and the problem I have is that when I use protoc to generate the python class. The file that’s generated looks nothing like in the example provided by Google and cannot be imported in any file because there are some unresolved references.
So I followed the example from this page: https://developers.google.com/protocol-buffers/docs/pythontutorial

Preconditions

1. Operating system macOS 12.6 on M1 Mac.
2. I used Python 3.9.11 in a vrtualenv managed with pyenv and pyenv-virtualenv
3. I downloaded the latest python package from https://github.com/protocolbuffers/protobuf/releases/tag/v21.7
4. I installed protobuf with homebrew https://formulae.brew.sh/formula/protobuf
5. I followed this instruction to install the package https://github.com/protocolbuffers/protobuf/tree/v21.7/python
6. I also copiled the c++ protoc from the above protobuff package to see if it helps but it didn’t

The packages I had in the end were:

$ python --version
$ Python 3.9.11
$ 
$ protoc --version
$ libprotoc 3.21.7
$
$ pip freeze | grep protobuf
$ protobuf==3.20.2

The code

First I try to generate the a python class from this tutorial .proto file:

syntax = "proto2";

package tutorial;

message Person {
  optional string name = 1;
  optional int32 id = 2;
  optional string email = 3;

  enum PhoneType {
    MOBILE = 0;
    HOME = 1;
    WORK = 2;
  }

  message PhoneNumber {
    optional string number = 1;
    optional PhoneType type = 2 [default = HOME];
  }

  repeated PhoneNumber phones = 4;
}

message AddressBook {
  repeated Person people = 1;
}

Then I use the command to generate the python class

protoc -I=. --python_out=. tutorial.proto

And the output file is:

# -*- coding: utf-8 -*-
# Generated by the protocol buffer compiler.  DO NOT EDIT!
# source: tutorial.proto
"""Generated protocol buffer code."""
from google.protobuf.internal import builder as _builder
from google.protobuf import descriptor as _descriptor
from google.protobuf import descriptor_pool as _descriptor_pool
from google.protobuf import symbol_database as _symbol_database
# @@protoc_insertion_point(imports)

_sym_db = _symbol_database.Default()




DESCRIPTOR = _descriptor_pool.Default().AddSerializedFile(b'nx0etutorial.protox12x08tutorial"xd5x01nx06Personx12x0cnx04namex18x01 x01(tx12nnx02idx18x02 x01(x05x12rnx05x65mailx18x03 x01(tx12,nx06phonesx18x04 x03(x0bx32x1c.tutorial.Person.PhoneNumberx1aGnx0bPhoneNumberx12x0enx06numberx18x01 x01(tx12(nx04typex18x02 x01(x0ex32x1a.tutorial.Person.PhoneType"+ntPhoneTypex12nnx06MOBILEx10x00x12x08nx04HOMEx10x01x12x08nx04WORKx10x02"/nx0bx41x64x64ressBookx12 nx06peoplex18x01 x03(x0bx32x10.tutorial.Person')

_builder.BuildMessageAndEnumDescriptors(DESCRIPTOR, globals())
_builder.BuildTopDescriptorsAndMessages(DESCRIPTOR, 'tutorial_pb2', globals())
if _descriptor._USE_C_DESCRIPTORS == False:

  DESCRIPTOR._options = None
  _PERSON._serialized_start=29
  _PERSON._serialized_end=242
  _PERSON_PHONENUMBER._serialized_start=126
  _PERSON_PHONENUMBER._serialized_end=197
  _PERSON_PHONETYPE._serialized_start=199
  _PERSON_PHONETYPE._serialized_end=242
  _ADDRESSBOOK._serialized_start=244
  _ADDRESSBOOK._serialized_end=291
# @@protoc_insertion_point(module_scope)

So as you can see there are no metaclasses created and all the constants below the line DESCRIPTOR.options=None are Unresolved references.

When I try to import that file later, runtime obviously crashes as this is not a valid Python file.

Any ideas?