Update Subversion to 1.14.1 LTS. See contrib/subversion/CHANGES for a
summary of changes, or for a more thorough overview:

https://subversion.apache.org/docs/release-notes/1.14

NOTE 1: There is no need to dump and reload repositories, and the
working copy format is still the same as Subversion 1.8 through 1.13.

NOTE 2: The upstream release also contains a fix for a security issue in
mod_dav_svn (CVE-2020-17525), but since we do not build or use any
Apache modules, it is not an issue for the FreeBSD base system.

Relnotes: yes

(cherry-picked from 0ff1014944897f4f3ffa4462406cdee920b53400)