After talking with Drew, it seems that they are overhauling how the build system works with regards to packaging the artifacts.

So, we decided that the best course of action would be to run the sdam json tests as a separate executable that runs in it's own evergreen task rather than trying to get scons to reliably copy the files if anything changes.

This requires:
1. setting up a new evergreen task that grabs the json directly from the source tree as well as the sdam test runner executable.
2. making sure json test executable properly runs, and reports success or failure in evergreen