Add directories for attachment, mail, and s3 to Dockerfile-build

Added new directories for attachment, mail, and s3 to the build process.

build was failing with 

>16.61     │ server/server.go:39:2: no required module provides package heckel.io/ntfy/v2/mail; to add it:

Dockerfile-build

@@ -45,6 +45,9 @@ ADD ./db ./db
 ADD ./message ./message
 ADD ./model ./model
 ADD ./webpush ./webpush
+ADD ./attachment ./attachment
+ADD ./mail ./mail
+ADD ./s3 ./s3
 RUN --mount=type=cache,target=/go/pkg/mod --mount=type=cache,target=/root/.cache/go-build make VERSION=$VERSION COMMIT=$COMMIT cli-linux-server
 
 FROM alpine