samples: zephyr: drivers: adc: adc_dt: Disable on nrf54lm20pdk

Original sample in the Zephyr repository is now executed on
final board name of nrf54lm20dk/nrf54lm20a/cpuapp.

Disable execution on obsolete nrf54lm20pdk target.

Signed-off-by: Sebastian Głąb <[email protected]>

Author: nordic-segl

samples/zephyr/drivers/adc/adc_dt/boards/nrf54lm20pdk_nrf54lm20a_cpuapp.overlay

@@ -6,13 +6,8 @@ tests:
       - ci_samples_zephyr_drivers_adc
     # depends_on: adc
     integration_platforms:
-      - nrf54lm20pdk/nrf54lm20a/cpuapp
       - nrf54lv10dk/nrf54lv10a/cpuapp
     platform_allow:
-      - nrf54lm20pdk/nrf54lm20a/cpuapp
-      - [email protected]/nrf54lm20a/cpuapp
-      - [email protected]/nrf54lm20a/cpuapp
-      - [email protected]/nrf54lm20a/cpuapp
       - nrf54lv10dk/nrf54lv10a/cpuapp
       - [email protected]/nrf54lv10a/cpuapp
       - [email protected]/nrf54lv10a/cpuapp