Ensure java 6 compatable

[johnjaylward]

What problem does this code solve?

Adds back in the build/jar for java6 to help ensure binary source compatibility. This leaves the actual deployment to Maven Central as a Java 8 compatibility.

Sample build run: https://github.com/johnjaylward/JSON-java/actions/runs/6617867256

As part of the java6 build, I made sure to output the current version of the java compiler:

This PR also adds support for auto-uploading the JARs built during the "Deployment Workflow" to the GitHib release. See https://github.com/johnjaylward/JSON-java/releases/tag/20231023-SNAP-01 as an example of what the release would look like.

Does the code still compile with Java6?

Yes, that's what this PR is made to ensure.

Risks

To compile Java 1.6 on GitHub, it requires using the deprecated action "setup-java@v1". v2 and greater of the action do not support java6. It's unknown when GitHub will end support for this action completely. Once they do, builds will break and we will need to "cross compile" from a newer version of the JDK down to 1.6, which is not guaranteed to ensure full 1.6 compatibility.

Changes to the API?

No

Will this require a new release?

No

Should the documentation be updated?

No

Does it break the unit tests?

No. However, no testing is done against JDK 6. Only compilation of src/main and packing is performed. The JDK-1.6 jar that is uploaded to the build artifacts is also not compatible with JDK 9+ as no module information is provided

Was any code refactored in this commit?

No

Review status
APPROVED

Starting 3-day comment window

[stleary]

@johnjaylward Looks good, thanks!

[johnjaylward]

you removed the approved label but didn't merge. Was that intentional?

[stleary]

@johnjaylward My bad, it was still in the 3-day window. Going ahead and merging now.