Add a git-blame-ignore-revs file

'git blame' can ignore certain revisions when annotating, e.g. revisions that just reformatting.

Signed-off-by: Jelmer Vernooĳ <jelmer@samba.org>
Reviewed-by: Andrew Bartlett <abartlet@samba.org>

Autobuild-User(master): Andrew Bartlett <abartlet@samba.org>
Autobuild-Date(master): Fri Mar  3 02:02:51 UTC 2023 on atb-devel-224
