build: include annotations in the multi-arch images

This needs --annotations support in buildx which was introduced in
docker/buildx#2020 and will be released in
0.12.0.

.github/bin/get-buildx-args

@@ -11,6 +11,10 @@ else
     done
 fi
 
+# Expose annotations
+WEBLATE_VERSION=$(sed -n 's/^ENV WEBLATE_VERSION \(.*\)/\1/p' Dockerfile)
+sed -n "s/^LABEL \(org.opencontainers.image.*\)/--annotation \1/p" Dockerfile | sed "s/\\\$WEBLATE_VERSION/$WEBLATE_VERSION/"
+
 # Write to local cache unless publishing (not compatible with push)
 if [ "$1" != "publish" ] ; then
     echo --cache-to "type=local,dest=/tmp/.buildx-cache/$MATRIX_ARCHITECTURE,mode=max"

Dockerfile

@@ -11,7 +11,8 @@ LABEL org.opencontainers.image.url="https://weblate.org/"
 LABEL org.opencontainers.image.documentation="https://docs.weblate.org/en/latest/admin/install/docker.html"
 LABEL org.opencontainers.image.source="https://github.com/WeblateOrg/docker"
 LABEL org.opencontainers.image.version=$WEBLATE_VERSION
-LABEL org.opencontainers.image.vendor="Michal Čihař"
+LABEL org.opencontainers.image.author="Michal Čihař <[email protected]>"
+LABEL org.opencontainers.image.vendor="Weblate"
 LABEL org.opencontainers.image.title="Weblate"
 LABEL org.opencontainers.image.description="A web-based continuous localization system with tight version control integration"
 LABEL org.opencontainers.image.licenses="GPL-3.0-or-later"