Our libzim packages are "7.2.0~focal" but the ~ means that "7.2.0" is greater than
"7.2.0~focal" so the dependency can't be satisfied. Depending on "7.2.0~" will
allow "7.2.0~focal" to satisfy the dependency. Same for libkiwix.
zlib and microhttpd are used by libkiwix, not kiwix-tools.
We indeed need libzim, but we use no feature related to xapian so no
need to mark it as mandatory.
(Libkiwix needs it and the check is there)