Update EclipseLink doc to 4.0 (#1198)

Author: MonkeyCanCode

extension/persistence/eclipselink/src/main/java/org/apache/polaris/extension/persistence/impl/eclipselink/PolarisEclipseLinkSessionCustomizer.java

@@ -25,7 +25,7 @@
 /**
  * This pattern of injecting a SessionCustomizer is taken from the EclipseLink guide documentation:
  *
- * <p>https://eclipse.dev/eclipselink/documentation/2.6/dbws/creating_dbws_services002.htm
+ * <p>https://eclipse.dev/eclipselink/documentation/4.0/dbws/dbws.html#performing-intermediate-customization
  */
 public class PolarisEclipseLinkSessionCustomizer implements SessionCustomizer {
   @Override

site/content/in-dev/unreleased/metastores.md

@@ -51,13 +51,13 @@ on the type of database and its configuration.
 
 > Note: You have to locate the `persistence.xml` at least two folders down to the root folder, e.g. `/deployments/config/persistence.xml` is OK, whereas `/deployments/persistence.xml` will cause an infinity loop.
 [Quarkus Configuration Reference]: https://quarkus.io/guides/config-reference
-[EclipseLink configuration file]: https://eclipse.dev/eclipselink/documentation/2.5/solutions/testingjpa002.htm
+[EclipseLink configuration file]: https://eclipse.dev/eclipselink/documentation/4.0/solutions/solutions.html#TESTINGJPA002
 
 Polaris creates and connects to a separate database for each realm. Specifically, the `{realm}` placeholder in `jakarta.persistence.jdbc.url` is substituted with the actual realm name, allowing the Polaris server to connect to different databases based on the realm.
 
 > Note: some database systems such as Postgres don't create databases automatically. Database admins need to create them manually before running Polaris server.
 
-A single `persistence.xml` can describe multiple [persistence units](https://eclipse.dev/eclipselink/documentation/2.6/concepts/app_dev001.htm). For example, with both a `polaris-dev` and `polaris` persistence unit defined, you could use a single `persistence.xml` to easily switch between development and production databases. Use the `persistence-unit` option in the Polaris server configuration to easily switch between persistence units.
+A single `persistence.xml` can describe multiple [persistence units](https://eclipse.dev/eclipselink/documentation/4.0/concepts/concepts.html#APPDEV001). For example, with both a `polaris-dev` and `polaris` persistence unit defined, you could use a single `persistence.xml` to easily switch between development and production databases. Use the `persistence-unit` option in the Polaris server configuration to easily switch between persistence units.
 
 ### Using H2