On move-tracking-3 branch, block (record-only) merge of r1915903 from trunk

This branch (move-tracking-3) exists to keep, for historical reference, a
prototype/experiment of move-tracking and branching. This branch was formed
from trunk at r1915902 and then the work being preserved here was removed from
trunk in r1915903.

Per the BRANCH-README, the merge policy is "Development branch -- periodic
catch-up merges from trunk." Unfortunately, the first thing such a catch-up
merge would do is to merge r1915903, which would delete what we're trying to
preserve. To avoid that, blocking that revision by a record-only merge,
updating mergeinfo.

See the dev@ email thread "Removing the old move-tracking experiment" started
on 2024 Feb 19, archived here (and elsewhere):
https://lists.apache.org/thread/wzv8k2y5jk5c8vwhhns4d8t6on7ld317

* .,
  notes/move-tracking/README,
  subversion/libsvn_fs_x,
  subversion/libsvn_subr/utf8proc,
  tools/buildbot/slaves/win32-vcpkg
  (svn:mergeinfo): Record-only merge of r1915903


git-svn-id: https://svn.apache.org/repos/asf/subversion/branches/move-tracking-3@1915925 13f79535-47bb-0310-9956-ffa450edef68