main to JDK 11?

[bradh]

The minimum build for the main branch is currently JDK 1.8.

JDK 1.8 is EOL for active support, although it does have security support through to 2030 (from https://endoflife.date/java and https://www.oracle.com/java/technologies/java-se-support-roadmap.html).

Dependencies are starting to move to JDK 11 (e.g. TestNG won't build on JDK 8 from 7.6.0 - see #439 for an attempt), and while the TestNG CVE looks to be pretty bogus, there will eventually be something we really do need to upgrade.

One option would be to switch the main branch to JDK 11. That has support to September 2023, and seems to be reasonably well supported.

We could just move to the 2.x branch for active development, but I still have a lot of work to do that could be breaking changes, and not a lot of spare time to work on it.

@wlfgang are you OK with JDK 11 only (no JDK 1.8 or JDK 17) for main?