ci: add JDK 25, switch to temurin distribution, refactor

[cortlepp]

Add JDK 25 to the list of supported and tested Java versions. To achieve this, I

• added JDK 25 to our CI matrix (and refactored our configuration for easier extensibility).
• shielded SecurityManager usages by a runtime check, so that we only use it on supported JVMs (the current solution works, but the JDK documentation discourages just delegating to the deprecated methods link).
• removed some build warnings by no longer including the ant runtime in several tasks.
• removed the hermetic-maven-plugin, as it depends on the SecurityManager. I don't think it was ever required, but maybe @veithen can give some background on this and whether additional steps have to be taken.
• removed the animal-sniffer-maven-plugin as it is no longer used anywhere.
• updated some plugins to make them compatible with JDK 25

[cortlepp]

@robertlazarski do you still want to look over this or can I just merge it?

[robertlazarski]

@cortlepp this looks great and thanks for reminding me, I was traveling the week you posted this and meant to revisit it but never did.

If there are any other outstanding questions you have and/or reviews that have been neglected, feel free to reach out like you did today.