west.yml: hal_stm32: Don't include legacy headers anymore

We're not supposed to rely on symbols provided by these files.
In case it is required stm32 zephyr code base should be updated rather
than relying on legacy definitions.

Additionally:
Fixes https://github.com/zephyrproject-rtos/zephyr/issues/70136



Signed-off-by: Erwan Gouriou <erwan.gouriou@st.com>