audio/re: Fix build on 15-CURRENT and 14-STABLE

Details:

• Recent changes on head[1] and stable/14[2] cause the resolv detection in audio/re to add -lresolv to the linker flags, which is not available on FreeBSD.

[1] https://cgit.freebsd.org/src/commit/?id=58cf91d3b72a01777bacf72d66a648a744ae3143
[2] https://cgit.freebsd.org/src/commit/?h=stable/14&id=5a70219b209f4ba8e8244d3886d364da4c00e4df

Reported by: Herbert J. Skuhra <herbert@gojira.at>