[clang-tidy] Fix some false negatives in `readability-redundant-typename` (#171947)
#169166 reported some false positives in this check. They stemmed from
the fact that it assumed `TypedefTypeLoc`s and `TagTypeLoc`s couldn't be
dependent. Turns out, this incorrect assumption leads to some false
*negatives* as well: https://godbolt.org/z/K6EvfrE6a. This PR fixes
those.