Fix default no-response behavior for force listen only

[MrAlaskan]

Summary

This PR fixes the default behavior of diag_force_listen_only().

Previously, the method used no_response_expected=False by default, so the client would wait for a reply after sending Force Listen Only Mode.

According to the Modbus specification for Diagnostics sub-function 0x08 / 0x0004, no response is returned for this request.

Change

• Before: diag_force_listen_only(..., no_response_expected=False)
• After: diag_force_listen_only(..., no_response_expected=True)

Rationale

This aligns the client default behavior with the protocol and with the method's own docstring, which already states that no response is returned.

Without this change, a default call to diag_force_listen_only() can incorrectly fall into a timeout or retry path even when the request was successfully accepted by the remote device.

[janiversen]

You can actívate or deactivate the function, so the default value does not really matter.

However your point about the documentation is correct.

Thanks