archivers/rpm4: update to 4.18.1

Major changes:
    Preserve packages bit-by-bit again when adding and then removing signatures
    Fix install of block and character special files
    Disable debuginfod server lookups during package builds
    Plugin fixes (fapolicyd and selinux)
    Various OpenPGP and macro parser fixes

Remove html documentation for librpm
Cleanup/reorder Makefile to make linter happy

Full changelog: https://rpm.org/wiki/Releases/4.18.1