schema_registry/tests: Use protobuf/payload.proto for python kafka-serde

The proto has been generated by protoc. I'd prefer to have put it as
part of the build system, but I can't. Maybe somebody else can.

```
cd tests/protobuf
../../vbuild/debug/clang/rp_deps_install/bin/protoc --python_out=../rptest/remote_scripts payload.proto
```

Signed-off-by: Ben Pope <ben@redpanda.com>

.yapfignore

@@ -3,5 +3,6 @@ build/*
 vtools/*
 depot_tools/*
 src/v/dashboard/node_modules/*
+tests/rptest/remote_scripts/payload_pb2*
 go/*
 .git/*

tests/rptest/remote_scripts/python_librdkafka_serde_client.py

@@ -22,8 +22,7 @@
 from confluent_kafka.schema_registry.avro import AvroDeserializer, AvroSerializer
 from confluent_kafka.schema_registry.protobuf import ProtobufDeserializer, ProtobufSerializer
 
-from google.protobuf.descriptor_pb2 import FieldDescriptorProto
-from google.protobuf import proto_builder
+from payload_pb2 import Payload as ProtobufPayloadClass
 
 
 class SchemaType(IntEnum):
@@ -50,10 +49,6 @@ def val(self):
 }
 '''
 
-ProtobufPayloadClass = proto_builder.MakeSimpleProtoClass(
-    OrderedDict([('val', FieldDescriptorProto.TYPE_INT64)]),
-    full_name="example.Payload")
-
 
 def make_protobuf_payload(val: int):
     p = ProtobufPayloadClass()

tests/rptest/services/serde_client.py

@@ -78,6 +78,7 @@ def __init__(self,
     def _worker(self, idx, node):
 
         if self._serde_client_type == SerdeClientType.Python:
+            inject_remote_script(node, "payload_pb2.py")
             script_path = inject_remote_script(
                 node, "python_librdkafka_serde_client.py")
             script_path = f"{PYTHON_EXEC} {script_path}"

tests/setup.py

@@ -9,17 +9,29 @@
     author_email='hi@vectorized.io',
     description='vectorized internal testing',
     packages=find_packages(),
-    setup_requires=['setuptools'],
+    setup_requires=['setuptools', 'grpcio-tools==1.53'],
     package_data={'': ['*.md']},
     include_package_data=True,
     install_requires=[
         'ducktape@git+https://github.com/redpanda-data/ducktape.git@5b4c31648d8f94d3f28113a6fa0377339aa222ed',
-        'prometheus-client==0.9.0', 'pyyaml==6.0', 'kafka-python==2.0.2',
-        'crc32c==2.2', 'confluent-kafka==2.0.2', 'zstandard==0.15.2',
-        'xxhash==2.0.2', 'protobuf==3.19.5', 'fastavro==1.4.9',
-        'psutil==5.9.0', 'numpy==1.22.3', 'pygal==3.0', 'pytest==7.1.2',
-        'jump-consistent-hash==3.2.0', 'azure-storage-blob==12.14.1',
-        'kafkatest@git+https://github.com/apache/kafka.git@058589b03db686803b33052d574ce887fb5cfbd1#egg=kafkatest&subdirectory=tests'
+        'prometheus-client==0.9.0',
+        'pyyaml==6.0',
+        'kafka-python==2.0.2',
+        'crc32c==2.2',
+        'confluent-kafka==2.0.2',
+        'zstandard==0.15.2',
+        'xxhash==2.0.2',
+        'protobuf==4.21.8',
+        'fastavro==1.4.9',
+        'psutil==5.9.0',
+        'numpy==1.22.3',
+        'pygal==3.0',
+        'pytest==7.1.2',
+        'jump-consistent-hash==3.2.0',
+        'azure-storage-blob==12.14.1',
+        'kafkatest@git+https://github.com/apache/kafka.git@058589b03db686803b33052d574ce887fb5cfbd1#egg=kafkatest&subdirectory=tests',
+        'grpcio==1.53.0',
+        'grpcio-tools==1.53',
     ],
     scripts=[],
 )