Remove hack_dependency_not_implemented

[gilles-peskine-arm]

In generate_psa_tests.py (if not moved or renamed by the implementation of #7845 by the time you read this), there is a function hack_dependencies_not_implemented which skips symbols for which dependencies are not available.

At this point, all PSA_WANT symbols are implemented, so this function is no longer necessary. However, it still triggers on test cases that are enumerated for algorithms/curves/… that we don't implement, and we may want to handle those specially. That should not be based on some fragile parsing, however: we should have a whitelist of non-implemented algorithms somewhere, and make sure that for those algorithms we generate a “not supported” test case.