Fix configuration for PS v5 and v6 builds to be Debug/Release and not PSV6Debug, etc. as it used to be able to produce actual debug builds

[bergmeister]

PR Summary

The special PSV4Debug and PSV3Debug configurations apply only to builds of v3 and v4. The other builds do not need that and should just be Debug/Release as a config. At the moment this makes Debug build actually be Release builds, which this PR fixes. cc @thomasrayner
This minor regression was introduced in the build module refactoring of PR #1139

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