Java 27 support

As of today (10 June 2026) [JaCoCo version 0.8.15](https://github.com/jacoco/jacoco/releases/tag/v0.8.15) already supports not yet released [Java 27](https://jdk.java.net/27/).
And we believe that no additional changes will be required, other than documentation update.