Dropping Java 8, and going with Java 17

[dmikurube]

JRuby seems considering to drop Java 8 from their next major version (9.5?).
https://twitter.com/headius/status/1641463288176189441

Java open-source softwares still tended to stay with Java 8 until last year, but the trend may be changing.

It may be a good time also for us to start thinking about dropping Java 8 someday (although JRuby is not a show-stopper for us because JRuby is optional since v0.10).

For example (just one of ideas, nothing determined):

• Embulk v0.11: To be built with Java 8, but to support/test to run on Java 17 officially at some point in v0.11.
• Embulk v1.0: To be built with Java 17. (It won't run with Java 8.)

@embulk/core-team Wanted to hear your thoughts.

[kakoni]

I've been running v0.11 with JRuby 9.4.3.0 and Java 17 successfully (https://github.com/kakoni/embulk_docker/tree/main) for sometime now.

[dmikurube]

Thanks for your information!

[dmikurube]

Please share any issues / blockers / incompatibilities you found in using newer Java versions! ↓