JavaxPersistenceXmlToJakartaPersistenceXml finds persistence descriptors by namespace instead of file name

[jkschneider]

The recipe only looked at files named persistence.xml, so descriptors kept under other names, such as Arquillian's test-persistence.xml, stayed on the Java EE namespace and version 2.0. Its precondition now matches any XML document whose root is persistence in the http://java.sun.com/xml/ns/persistence or http://xmlns.jcp.org/xml/ns/persistence namespace, whatever the file is called. Unrelated XML with a persistence root is left alone, and so is a persistence.xml already on the Jakarta namespace, which the file name check used to set back to version 3.0 even when it was 3.2.

Found by a team of coding agents reviewing a Moderne run of org.openrewrite.java.migrate.jakarta.JavaxMigrationToJakarta over the 31 Arquillian repositories (run 20261003120559-YQoma). The issue is custom-persistence-descriptor-skipped in the run's io.moderne.RecipeIssues data table (10 rows), and the fix was discussed and reviewed on the run's message board. A row from the table, as a generalized example:

Persistence descriptors packaged under a different filename are left in the Java EE namespace. (arquillian/arquillian-extension-persistence, int-tests/src/test/resources-wildfly-8.1.0/test-persistence.xml, recipe org.openrewrite.java.migrate.jakarta.JavaxMigrationToJakarta)

Before:

// src/test/resources/test-persistence.xml
<persistence xmlns="http://java.sun.com/xml/ns/persistence" version="2.0"/>

What the recipe produced:

// src/test/resources/test-persistence.xml
<persistence xmlns="http://java.sun.com/xml/ns/persistence" version="2.0"/>

Expected:

// src/test/resources/test-persistence.xml
<persistence xmlns="https://jakarta.ee/xml/ns/persistence" version="3.0"/>

Stacked on #1268 (6 of 19); merge that one first.