Have you read the Contributing Guidelines on issues?

• I have read the Contributing Guidelines on issues.

Prerequisites

• I'm using the latest version of pact-python.
• I have read the console error message carefully (if applicable).

Description

When using MessageConsumer and attempting to set an iso_8601_datetime matcher, the pact file generation fails on Windows. This issue does not occur on Linux, where it works as expected.

Reproducible demo

No response

Steps to reproduce

Run this script on windows:

# consumer.py
from pact import MessageConsumer, Provider, matchers


# Função principal do consumer
def run_consumer():
    # Define o contrato do consumer
    contract = MessageConsumer(
        "my_contract Consumer"
    ).has_pact_with(
        Provider("my_contract Provider"),
        pact_dir="pacts",
    )

    # Define os dados do evento
    event_data = {
        "invoice_id": "12345",
        "amount": 100.00,
        "currency": "USD",
        "created": matchers.Format().iso_8601_datetime(),
    }

    # Cria uma mensagem que representa o evento
    contract.given("Create contract").expects_to_receive(
        "An event of contract").with_content(event_data)

    with contract:
        pass

if __name__ == "__main__":
    run_consumer()

Please note that the file will not be generated.

If you set a breakpoint on message_pact.py, line 193, you can observe that the issue occurs during:
json.dumps(self._messages[0]),

It seems to be something related with regex and json dumps
Remember: it only happens on windows

Expected behavior

The file must be generated on windows

Actual behavior

If matchers.Format().iso_8601_datetime() is used, the local pact file is not being generated on windows

Your environment

Windows 11

Self-service

• I'd be willing to fix this bug myself.