Upgrading Apache XBean to allow JDK compatibility up to 26 (#139)

diff --git a/pom.xml b/pom.xml
index 4e56203..e2e46be 100644
--- a/pom.xml
+++ b/pom.xml
@@ -26,7 +26,7 @@
     <parent>
       <groupId>org.apache</groupId>
       <artifactId>apache</artifactId>
-      <version>34</version>
+      <version>35</version>
     </parent>
 
     <groupId>org.apache.openjpa</groupId>
@@ -91,7 +91,7 @@
         <javadoc.additionalparam />
         <version.maven.surefire>3.5.2</version.maven.surefire>
 
-        <xbean.version>4.26</xbean.version>
+        <xbean.version>4.28</xbean.version>
         <bval.version>3.0.2</bval.version>
         <log4j2.version>2.23.1</log4j2.version>
         <ant.version>1.10.15</ant.version>