Update jenkins version to 2.504.3 to facilicate bom validations (#1775)

Author: Vlatombe

pom.xml

@@ -44,7 +44,7 @@
     <jenkins.host.address />
     <slaveAgentPort />
     <jenkins.baseline>2.504</jenkins.baseline>
-    <jenkins.version>${jenkins.baseline}.1</jenkins.version>
+    <jenkins.version>${jenkins.baseline}.3</jenkins.version>
     <no-test-jar>false</no-test-jar>
     <useBeta>true</useBeta>
     <gitHubRepo>jenkinsci/${project.artifactId}-plugin</gitHubRepo>