JPMS appeared in Java 9, now Java 14 is available. Starting from Java 9 we have two types of path:
– class-path and --module-path. If JPMS is used in application then, as a rule, no class-path is used.

So I suggest to add scanning for `persistence.xml` also in module-path. Although according to JPA specs persistence.xml file has to be located in the META-INF directory in the classpath, all we know that there was no JPMS when JPA specs was written.