use apt-get instead of apt and --no-install-recommends option

Co-authored-by: Milas Bowman <milasb@gmail.com>
Signed-off-by: Guillaume Lours <guillaume.lours@docker.com>

traefik-golang/backend/Dockerfile

@@ -9,8 +9,8 @@ RUN CGO_ENABLED=0 go build -o backend main.go
 FROM build as dev-envs
 
 RUN <<EOF
-apt update
-apt install git
+apt-get update
+apt-get install -y --no-install-recommends git
 EOF
 
 RUN <<EOF