Set Maven compiler release to 17

the library should not float java versions nor pick them up from the parent pom.

The library is consumed by plugins, via the plugin-pom and upgrading the bytecode will cause the plugin pom to no longer work with older (pre 25) versions of Jenkins and there is no need to do that.

Author: jtnord

pom.xml

@@ -26,6 +26,7 @@
     <gitHubRepo>jenkinsci/lib-${project.artifactId}</gitHubRepo>
     <spotless.check.skip>false</spotless.check.skip>
     <ban-junit4-imports.skip>false</ban-junit4-imports.skip>
+    <maven.compiler.release>17</maven.compiler.release>
   </properties>
 
   <dependencies>