Fix explorer release pipeline post actions

15:59:05  Error when executing unsuccessful post condition:
15:59:05  java.lang.NullPointerException: Cannot invoke method isEmpty() on null object
15:59:05  	at org.codehaus.groovy.runtime.NullObject.invokeMethod(NullObject.java:91)
15:59:05  	at org.codehaus.groovy.runtime.callsite.PogoMetaClassSite.call(PogoMetaClassSite.java:48)
15:59:05  	at org.codehaus.groovy.runtime.callsite.CallSiteArray.defaultCall(CallSiteArray.java:48)