[Relax] Additional unit tests for RemoveUnusedParameters

[Lunderberg]

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Verifying behavior for subroutines that receive R.Prim or R.Shape parameters, if the symbolic variables defined by those parameters are already defined by another parameter.

[Lunderberg]

This test case was written to verify the statements I made in this comment. Adding them to the CI, as it was behavior of RemoveUnusedParameters that wasn't previously being tested.