Run `libsyclinterface` test suite with open source compiler or in open source compiler workflow

[ndgrigorian]

While Python and libsyclinterface tests generally touch the same code, it's possible that changes could be disruptive to libsyclinterface while being masked by Python tests

Test failures may not need to fail the workflow (after all, the OS compiler is unstable as-is) but would be gppd to see what breaks