fix: upgrade lombok and compiler plugin for Java 21

[bjagg]

Upgrade Lombok and compiler plugin for Java 21 compatibility

[Copilot]

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• pom.xml: Language not supported

[Naenyn]

Not sure how to undo my approval! Heh. Anyway, I tried your branch locally:

java.lang.IllegalStateException: Failed to load ApplicationContext Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'entityManagerFactory' defined in class path resource [context/databaseContext.xml]: Invocation of init method failed; nested exception is java.lang.ExceptionInInitializerError Caused by: java.lang.ExceptionInInitializerError Caused by: java.lang.reflect.InaccessibleObjectException: Unable to make protected final java.lang.Class java.lang.ClassLoader.defineClass(java.lang.String,byte[],int,int) throws java.lang.ClassFormatError accessible: module java.base does not "opens java.lang" to unnamed module @483bf400