PL/Java warnings about future deprecations

[tilmanb]

Installing the PL/Java function reports these warnings:

WARNUNG:  [JEP 411] migration advisory: there will be a Java version (after Java 17) that will be unable to run PL/Java 1.6.3 with policy enforcement
DETAIL:  This PL/Java version enforces security policy using important Java features that will be phased out in future Java versions. Those changes will come in releases after Java 17.
HINT:  For migration planning, Java versions up to and including 17 remain fully usable with this version of PL/Java, and Java 17 is positioned as a long-term support release. For details on how PL/Java will adapt, please bookmark https://github.com/tada/pljava/wiki/JEP-411

This will need to be monitored

[tfr42]

Thanks for the reminder. Currently Java 11 is the target JDK version for sep3-tools. More information about PL/Java on JDK 17+ in https://github.com/tada/pljava/wiki/ and https://github.com/tada/pljava/wiki/JEP-411.