Linking `jemalloc` against executables is enough to replace *all* malloc
functionality with `jemalloc`. Linking it against a library will cause
issues for example with Python bindings. The downside is that Python
won't be using `jemalloc` by default, but likely malloc won't be the
bottleneck when using Python.
This enables us to completely skip the `include` folder when building
with `-DWITH_LIBDWARFS=OFF`. Otherwise, we're using includes that will
potentially not match the includes of the installed library.
