libguestfs 1.45.3 now reads the RPM database using librpm, which means
our old phony database created by db_dump can no longer work. Instead
provide a real (but very minimal) sqlite database.
This commit also fixes the virt-inspector test since the RPM database
contents are now different.
(cherry picked from commit 46bf6fb473889ed28bd7220476120edcda47ae07)