write-file-hooks is obsolete since Emacs 22.1 (released June 2007) and
it's time to use the recommended replacement.
Problem reported by Glenn Morris in:
https://lists.gnu.org/r/bug-gnulib/2018-03/msg00008.html
* build-aux/announce-gen, build-aux/bootstrap:
* build-aux/do-release-commit-and-tag, build-aux/gendocs.sh:
* build-aux/git-version-gen, build-aux/gitlog-to-changelog:
* build-aux/gnu-web-doc-update, build-aux/gnupload:
* build-aux/move-if-change, build-aux/prefix-gnulib-mk:
* build-aux/update-copyright, build-aux/useless-if-before-free:
* build-aux/vc-list-files:
Update hook usage for files where Gnulib is the canonical source.