Readme update to reflect current versioning (#1696)

Signed-off-by: Radek Felcman <radek.felcman@oracle.com>

README.md

@@ -11,12 +11,12 @@
 [![Language grade: Java](https://img.shields.io/lgtm/grade/java/g/eclipse-ee4j/eclipselink.svg?logo=lgtm&logoWidth=18)](https://lgtm.com/projects/g/eclipse-ee4j/eclipselink/context:java)
 [![Total alerts](https://img.shields.io/lgtm/alerts/g/eclipse-ee4j/eclipselink.svg?logo=lgtm&logoWidth=18)](https://lgtm.com/projects/g/eclipse-ee4j/eclipselink/alerts/)
 
-EclipseLink master (3.1.x)
-[![Maven Central](https://img.shields.io/maven-central/v/org.eclipse.persistence/eclipselink.svg?versionPrefix=3.1&label=Maven%20Central)](https://mvnrepository.com/artifact/org.eclipse.persistence/eclipselink)
+EclipseLink master (4.0.x)
+[![Maven Central](https://img.shields.io/maven-central/v/org.eclipse.persistence/eclipselink.svg?versionPrefix=4.0&label=Maven%20Central)](https://mvnrepository.com/artifact/org.eclipse.persistence/eclipselink)
 [![Jakarta Staging (Snapshots)](https://img.shields.io/nexus/s/https/jakarta.oss.sonatype.org/org.eclipse.persistence/eclipselink.svg)](https://jakarta.oss.sonatype.org/content/repositories/staging/org/eclipse/persistence/eclipselink)
 [![Master Build Status](https://ci.eclipse.org/eclipselink/job/eclipselink-nightly-master/badge/icon)](https://ci.eclipse.org/eclipselink/job/eclipselink-nightly-master)
 
-EclipseLink 3.0.0
+EclipseLink 3.0.x
 [![Maven Central](https://img.shields.io/maven-central/v/org.eclipse.persistence/eclipselink.svg?versionPrefix=3.0&label=Maven%20Central)](https://mvnrepository.com/artifact/org.eclipse.persistence/eclipselink)
 [![3.0 Build Status](https://ci.eclipse.org/eclipselink/job/eclipselink-nightly-3.0/badge/icon)](https://ci.eclipse.org/eclipselink/job/eclipselink-nightly-3.0)