Use `Arrays.hashCode(...)` in `ObjectUtils`

[j3graham]

java.util.Arrays has methods for hashCode generation on primitive arrays that are equivalent to nullSafeHashCode

They do however calculate different hash values. If this was tolerable, then the JDK methods could be used.

[j3graham]

Found an existing pr - #25594

[snicoll]

The PR has been declined so let's reconsider this particular change.