Update Gitea to 1.16.9

This is a bugfix release that gitea suggests we update to for important
fixes.

Changelog can be found at:
  https://github.com/go-gitea/gitea/blob/v1.16.9/CHANGELOG.md

One thing I note is the inclusion of support for git safe.directory in
newer git versions. Our bullseye git version is too old to support this,
but we also configure consistent users so this should be a non issue for
us.

Change-Id: I8c3e4e5eead13eeb72bee3ae6c8b89081cdc5cf0

docker/gitea/Dockerfile

@@ -27,7 +27,7 @@ FROM docker.io/library/golang:1.18-bullseye AS build-env
 
 LABEL maintainer="infra-root@openstack.org"
 
-ARG GITEA_VERSION="v1.16.8"
+ARG GITEA_VERSION="v1.16.9"
 ENV TAGS "bindata $TAGS"
 
 #Build deps