How to fix botocore.exceptions.ClientError: An error occurred (404) when calling the Invoke operation

I am trying to mock a lambda invocation using pytest and moto. Below is my working code.

import zipfile
import os
import boto3
from moto import mock_lambda,mock_iam
import pytest
import io
from botocore.exceptions import ClientError
import json


@pytest.fixture(scope='function')
def aws_credentials():
    """Mocked AWS Credentials for moto."""
    os.environ['AWS_ACCESS_KEY_ID'] = 'testing'
    os.environ['AWS_SECRET_ACCESS_KEY'] = 'testing'
    os.environ['AWS_SECURITY_TOKEN'] = 'testing'
    os.environ['AWS_SESSION_TOKEN'] = 'testing'


@pytest.fixture(scope='function')
def lambda_mock(aws_credentials):
    with mock_lambda():
        yield boto3.client('lambda', region_name='us-east-1')
        
def get_role_name():
    with mock_iam():
        iam = boto3.client("iam", region_name='us-east-1')
        try:
            return iam.get_role(RoleName="my-role")["Role"]["Arn"]
        except ClientError:
            return iam.create_role(
                RoleName="my-role",
                AssumeRolePolicyDocument="some policy",
                Path="/my-path/",
            )["Role"]["Arn"]
            

@pytest.fixture(scope='function')
def lambda_mock(aws_credentials):
       with mock_lambda():
           yield boto3.client('lambda', region_name='us-east-1')
           
def _process_lambda(func_str):
    zip_output = io.BytesIO()
    zip_file = zipfile.ZipFile(zip_output, "w", zipfile.ZIP_DEFLATED)
    zip_file.writestr("lambda_function.py", func_str)
    zip_file.close()
    zip_output.seek(0)
    return zip_output.read()


def get_test_zip_file1():
    pfunc = """
def lambda_handler(event, context):
    print("custom log event")
    return "hello world"
"""
    return _process_lambda(pfunc)
# create mocked lambda with zip file


@mock_lambda
def test_mock_some_lambda(lambda_mock):
    lambda_mock.create_function(
        FunctionName='abc',
        Runtime='python3.7',
        Role=get_role_name(),
        Handler='lambda_function.lambda_handler',
        Code={"ZipFile": get_test_zip_file1()},
        Publish=True,
        Timeout=30,
        MemorySize=128
    )
    resp=lambda_mock.invoke(FunctionName='abc')
    response=json.load(resp['Payload'])
    assert response=='hello world'

However, I want to separate lambda mocking and my testing function. So I created a pytest fixture which creates a lambda function like below.

@pytest.fixture(scope='function')
def mock_some_lambda(lambda_mock):
    yield lambda_mock.create_function(
        FunctionName='abc',
        Runtime='python3.7',
        Role=get_role_name(),
        Handler='lambda_function.lambda_handler',
        Code={"ZipFile": get_test_zip_file1()},
        Publish=True,
        Timeout=30,
        MemorySize=128
    )

And then a new test function which uses this fixture

@mock_lambda
def test_update_allowed(lambda_mock,mock_some_lambda):
    resp=lambda_mock.invoke(FunctionName='abc')
    response=json.load(resp['Payload'])
    assert response=='hello world'

This throws botocore.exceptions.ClientError: An error occurred (404) when calling the Invoke operation:

Looks like the lambda function creation is not sticking in the test function and when I run invoke(), it's not able to find the function.

How do I make this work ?