Find a new incompatible locale for tst_QLocale::defaulted_ctor() to test with

Some of the tst_QLocale::defaulted_ctor() tests used en_FR as requested default locale, deliberately because there was no such locale, but CLDR v47 has added an actual en_FR locale, causing these tests to just get what they asked for, so we no longer test that the fall-back from an unsatisfiable request goes according to plan. The update to v47 just changed the tests to get the result they did which, while correct, loses a class of testing.

I need to find another language / territory combination that's not present in CLDR to replace en_FR in these tests, with its actual fallback replacing en_US.