[pom] Downgrade eclipse.jdt-core to 3.31.0 as broken with mockito when - Fixes #712

[hazendaz]

now fixed at eclipse but will be in 4.30 release.

Fixes #712

[hazendaz]

note: I've been successfully forcing this down on many projects for months without any harm. Left everything else. Like most things eclipse these days they won't fix prior versions. So this is expected fixed upon 4.30 eclipse release.

[ctubbsii]

This would regress us to the version of the JDT Core for this formatter's 2.21 release. I've successfully been using 2.23 without any issue whatsoever. I don't understand the specifics of the issue you're seeing, but it clearly doesn't affect everybody. I would suggest that rather than hold this plugin back to that older version of JDT Core, and leave users uncertain about which version of Eclipse formatting this plugin matches up to as per https://code.revelc.net/formatter-maven-plugin/eclipse-versions.html, that we just hold off making new releases until Eclipse 4.30, which will probably be JDT 3.36. No point in regressing this plugin's JDT Core and creating further confusion, and I don't see any urgency to release sooner (I think we've basically already skipped Eclipse 4.28 and 4.29 and nobody's been complaining asking for a new release).

[hazendaz]

The issue is due to usage of static import on mockito 'when' method. As eclipse has documented they entirely broke that for last 2 releases. Its now fixed in eclipse 4.30 per eclipse-jdt/eclipse.jdt.core#1436 last month. I'm fine waiting but as noted, any user using mockito with static imports against 'when' is either doing what I've been doing or they simply are not up to date.

This only impacts those using static imports and they simply could stop doing that. Given I have to support some 2k repos, I cannot control who does or does not do that and its a good number in that model. Although I'm not on the latest either because caching is broken on latest per #757