Dockerfile: compile ejabberdapi during build

ecs/Dockerfile

@@ -1,3 +1,8 @@
+FROM docker.io/golang:1.20-alpine AS api
+RUN go install -v \
+    github.com/processone/ejabberd-api/cmd/ejabberd@master \
+    && mv bin/ejabberd bin/ejabberdapi
+
 FROM ejabberd/mix as builder
 ARG VERSION
 ENV VERSION=${VERSION:-latest} \
@@ -93,6 +98,7 @@ RUN apk upgrade --update-cache --no-progress \
 WORKDIR $HOME
 COPY --from=builder /ejabberd/runtime .
 COPY bin/* bin/
+COPY --from=api /go/bin/ejabberdapi bin/ejabberdapi
 RUN chmod 755 bin/ejabberdctl bin/ejabberdapi bin/erl
 COPY --chown=ejabberd:ejabberd conf conf/
 ADD --chown=ejabberd:ejabberd https://download.process-one.net/cacert.pem conf/cacert.pem