Update Minimum Java Version to 17

The minimum required Java version should be updated to 17 following the developer list discussion.

The Oracle Java SE Support Roadmap lists end of Premier Support for Java 11 on September 2023.

NiFi has supported Java 17 since version 1.16.0. With the removal of legacy modules, more libraries have Java 11 as a minimum version and some, such as Spring Framework 6, have adopted Java 17 as the minimum version.

Making Java 17 the minimum required version for NiFi 2.0.0 provides an extended lifecycle of support as opposed to Java 11, given current Java Long-Term Support policies.