tree-wide: Do not use package librt and libpthread

tree-wide: Do not use package librt and libpthread

The libraries libpthread, libdl, libutil, libanl have been integrated
into the libc library in version 2.34. it is not needed to explicitly
link them any more.

Most of the functions have been moved from the librt.so into libc.so
some time ago already.

Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>