Remove JDK 8 support out of the box

What does this MR do?

• Remove Out-of-the-box Java 8 support. The default/fallback version is retained to Java 17
• Remove java-maven-java-8-qa job as Java 8 is not supported anymore.
• Update report module

What are the relevant issue numbers?

• gitlab-org/gitlab#352549 (closed)
• gitlab-org/gitlab#353646 (closed)

Does this MR meet the acceptance criteria?

• Changelog entry added
• Documentation created/updated for GitLab EE, if necessary
• Documentation created/updated for this project, if necessary
• Documentation reviewed by technical writer or follow-up review issue created
• Tests added for this feature/bug
• Job definition updated, if necessary
  • Auto-DevOps template (also in CE)
  • Job definition example
  • CI Templates (to be removed)
  • Vendored CI Templates (also in CE)
• Conforms to the code review guidelines
• Conforms to the Go guidelines
• Security reports checked/validated by reviewer