fix(boards): kakutef7 disable optical flow ekf2 to save flash

kakutef7 overflows with nuttx 12.12.0 also it doesn't have optical
flow drivers anyhow. Thus disable ekf2 optical flow

Author: PetervdPerk-NXP

boards/holybro/kakutef7/default.px4board

@@ -29,6 +29,7 @@ CONFIG_MODULES_EKF2=y
 # CONFIG_EKF2_EXTERNAL_VISION is not set
 # CONFIG_EKF2_GNSS_YAW is not set
 # CONFIG_EKF2_MAGNETOMETER is not set
+# CONFIG_EKF2_OPTICAL_FLOW is not set
 # CONFIG_EKF2_RANGE_FINDER is not set
 # CONFIG_EKF2_SIDESLIP is not set
 CONFIG_MODULES_FLIGHT_MODE_MANAGER=y