Test batching barfs on incompatible features

The test batching feature (QTBUG-105273) currently complains when it combines tests that have no EXCEPTIONS with tests that have EXCEPTIONS. Probably ditto other such settings.

Example: https://testresults.qt.io/logs/qt/qtbase/1e9ee48364bd6727d9a414e48ae9cded6fab9ca8/LinuxopenSUSE_15_5x86_64LinuxWebAssemblyx86_64GCCqtci-linux-openSUSE-15.5-x86_64-52-88a0f7Sccache_UseConfigure/541b8d92b0e2c137e1c927e89c2018a0870b0837/build_1706909421/log.txt.gz

It appears the only work-around is to set NO_BATCH, which is wrong, because there are probably a lot of other tests that use the same feature set. Eventually, this will lead to all tests being forced into a uniform feature set (excluding useful tests like differing macros (QT_USE_STRINGBUILDER, QT_NO_CAST_FROM_ASCII) or C++ standards, or to a proliferation of NO_BATCH tests, rendering the feature moot.

Expected behaviour would be that batches are only formed from tests with compatible features, which would self-optimize batching.