GitHub Actions requires user ROOT

[JeroenKnoops]

Problem

Github Actions requires the user of the image to be ROOT otherwise it cannot checkout the repository.

Quick solution

Removing the java USER is possible, but it's also considered bad practice to create docker images with root.

Fix

In order to fix this issue, we will create a new docker-image with -gha (github actions) appended to the image tag.
The only difference with the original images are that they run with USER root

Images with USER root

In order to do this we need to do the following to images already running with user ROOT:

• Create new docker-image based on the original with -gha appended to the tag and add deprecation warning to the original. (see Append jdk images with -gha and add deprecation warning to original. #54)
• After a week, add USER java to original image

Images with USER java

In order to do this we need to do the following to images already running with user JAVA:

• Create new docker-image based on original image with USER: root and append tag with -gha.

This only applies to jdk images.