Remove Java 8 in platform defaults

[nmburgan]

We no longer support Java 8, and install the right Java we need in the specific projects that need it, so don't install Java 8 to avoid build confusion.

Short description

Checklist

I have:

• read the CONTRIBUTING.md document
• read and accepted the Developer Certificate of Origin document and added a Signed-off-by annotation to each of my commits
• read and accepted the AI Policy document and added Generated-by or Assisted-by annotations to each of my commits created with the help of an AI agent
• tested this code
• included documentation (including possible behaviour changes)
• documented the code
• added or modified regression test(s)
• added or modified unit test(s)