Add retry on state validation fail (faulty download case)

Rarely, the state validation can fail with:

java.lang.RuntimeException: java.lang.RuntimeException: java.lang.RuntimeException: java.io.IOException: Bad file descriptor
	at java.base/jdk.internal.reflect.DirectConstructorHandleAccessor.newInstance(DirectConstructorHandleAccessor.java:62)
	at java.base/java.lang.reflect.Constructor.newInstanceWithCaller(Constructor.java:502)
	at java.base/java.lang.reflect.Constructor.newInstance(Constructor.java:486)
	at java.base/java.util.concurrent.ForkJoinTask.getThrowableException(ForkJoinTask.java:540)
	at java.base/java.util.concurrent.ForkJoinTask.reportException(ForkJoinTask.java:567)
	at java.base/java.util.concurrent.ForkJoinTask.join(ForkJoinTask.java:653)
	at com.hedera.statevalidation.validator.merkledb.ValidateLeafIndexHalfDiskHashMap.validateIndex(ValidateLeafIndexHalfDiskHashMap.java:133)
	at java.base/java.lang.reflect.Method.invoke(Method.java:580)
	at java.base/java.util.ArrayList.forEach(ArrayList.java:1596)
	at java.base/java.util.ArrayList.forEach(ArrayList.java:1596)

(see https://github.com/hashgraph/hedera-state-validator/actions/runs/20437384837/job/58722111156#logs as an example)
If the validation is re-run with the same node and round, it passes, which suggests that sometimes there can be a faulty download, and in this case, the job should be retried.

Start with ValidateLeafIndexHalfDiskHashMap.validateIndex, the method named in the failure trace, and inspect the state-validation job from the linked GitHub Actions run. Reproduce or review validation for the same node and round, then define the retry boundary around the faulty-download failure. Done means a transient validation failure reruns the job and a successful rerun is reported correctly.