test: Remove extended lint (cppcheck)

These are unreferenced in the CI and documentation, and have been since
2019 (see #17549).

I'm not sure the cppcheck is worthwhile. It takes a long time
to run (I think this is why it isn't in the normal lints), and right
now it only appears to find implicit constructors. The list of
exceptions is out of date. But if anyone wants to bring it back at any
time in the future they can do so from git history (and port it to Python).

Author: laanwj