[Java] Upgrade Java version used by toolchain to Java 21 or latest

### Describe the enhancement requested

As of today, Java 8 or higher is required to build Arrow. This is the version used to launch the Maven process and used by the plugins, including maven-compiler-plugin (and indirectly by `javac` or equivalent).

As the tools and plugins used by Arrow are dropping support for Java 8 bit by bit (and potentially Java 11 as well) and as the Java project also keeps introducing new features of potential interest to the community at a regular 6month cadence, updating the toolchain accordingly and regularly seems to become more and more important.

The proposal is to change Java version requirement to build Arrow to use the latest released version.

The proposal does not change the Java version requirement to use Arrow (which would be still Java 8 or possibly [Java 11 starting Arrow 18.0](https://github.com/apache/arrow/issues/38051)). This includes also unit testing.

To achieve this, work will be divided into multiple incremental steps:

- [ ] [[Java] Add support for JDK version cross-testing](https://github.com/apache/arrow/issues/43380)
- [ ] [Java] Enforce new Java version build requirement

### Component(s)

Continuous Integration, Developer Tools, Java

Start with the Maven process and maven-compiler-plugin settings described in the issue, then review the linked JDK cross-testing work before changing the build requirement. Done means Arrow builds with the latest released Java version while Java 8 remains the runtime and unit-testing requirement.

Written by the indexing model from the issue text.