manifest: Update nRF hw models to version compatible with nrfx3.9

Update the HW models module to:
3cfca0192ff84da919e9bc7978bcc2239cd6a395

This includes 2 changes:
* 3cfca01 UART: Model more accurately TASKS_FLUSH behaviour
* 25cbd28: 54L15: Change CLOKPOWER IRQ line (MDK 8.68, nrfx 3.9.0)

    WARNING! This change breaks backwards compatibility with SW
    which expected this line to be 270 for 54L15 devices,
    and therefore with MDKs < 8.68 & nrfx < 3.9.0.
    This change requires updating to the MDK >=8.68 and nrfx >=3.9.0
    if building using the 54L15 models.
    52 and 53 models are not affected.

    Change the CLOCK_POWER interrupt line from 270 to 261.
    This has changed in the latest MDK (8.68) and the new
    value is used in the latest nrfx (3.9.0) drivers.

Signed-off-by: Alberto Escolar Piedras <alberto.escolar.piedras@nordicsemi.no>