Fix inconsistency in unit tests related to testModel-reflections.xml

The META-INF/reflections/testModel-reflections.xml file is created by ReflectionsCollectTest, and its presence was expected in ReflectionsTest.testResourcesScanner(). The assertion wasn't always satisfied, depending on the order of execution of tests.

Make testResourcesScanner() exclude testModel-reflections.xml from scanned resources and change the assertion not to expect the excluded file.

This fixes random build failures when compiling the tests.