samples: net: prometheus: add filter to not build with Renesas RA FSP

Exclude CONFIG_HAS_RENESAS_RA_FSP as Renesas RA HAL has build error
with MbedTLS and Socket enabled
Description in https://github.com/zephyrproject-rtos/zephyr/issues/80121



Signed-off-by: The Nguyen <the.nguyen.yf@renesas.com>