Fix Image Build Errors on 2023.2.4f1+

[AndrewKahr]

Changes

• Updates Windows image build script to read the new modules.json format introduced in 2023.2.4f1
• Removed test builds of older images (activation fails on multiple project builds but those are EOL versions so considering them out of scope)
• Update test workflow to comply with new activation requirements

Fixes error seen here: https://github.com/game-ci/docker/actions/runs/7361389040

You cannot call a method on a null-valued expression.
At C:\scripts\HelperFunctions.ps1:46 char:8
+ return $rawPath.Replace('{UNITY_PATH}', $UnityPath)
+        ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : InvalidOperation: (:) [], ParentContainsErrorRec 
   ordException
    + FullyQualifiedErrorId : InvokeMethodOnNull

The command 'powershell.exe -Command if ("$Env:module" -eq 'Android') { .\scripts\SetupAndroid.ps1 }' returned a non-zero code: 1
An image does not exist locally with the tag: unityci/editor
The push refers to repository [docker.io/unityci/editor]
The push refers to repository [docker.io/unityci/editor]
An image does not exist locally with the tag: unityci/editor
An image does not exist locally with the tag: unityci/editor
The push refers to repository [docker.io/unityci/editor]
Error: Process completed with exit code 1.

Checklist

• [x] Read the contribution guide and accept the code of conduct
• [x] Readme (updated or not needed)

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