cmake: add support for reproducible buildS
We should use relative path not absolute path. We can use target without
breaking reproducibility.
Origin: https://github.com/mroonga/mroonga/issues/298#issuecomment-
1030815927
Bug: https://github.com/mroonga/mroonga/issues/298
Forwarded: not-needed
Gbp-Pq: Name mroonga-mrn-lib-dirs-path-reproducible-build.patch