samples: crypto: rsa: Remove skip from sample.yaml

It's not correct to set `skip: true` together with
`intergration_platform`, therefore remove it.

Signed-off-by: Robert Lubos <[email protected]>

Author: rlubos

samples/crypto/rsa/sample.yaml

@@ -4,7 +4,6 @@ sample:
     name: RSA example
 tests:
     sample.rsa:
-        skip: true
         tags: introduction
         platform_allow: nrf5340dk_nrf5340_cpuapp_ns nrf5340dk_nrf5340_cpuapp nrf9160dk_nrf9160_ns nrf9160dk_nrf9160 nrf52840dk_nrf52840
         harness: console