Use apk --virtual instead of listing build time packages twice

Dockerfile

@@ -23,7 +23,16 @@ COPY ./requirements.txt /app
 
 ENV LLVM_CONFIG=/usr/bin/llvm9-config
 
-RUN apk add --no-cache \
+RUN apk add --no-cache --virtual .build \
+    autoconf \
+    automake \
+    g++ \
+    gcc \
+    jpeg-dev \
+    llvm9-dev\
+    make \
+    zlib-dev \
+    && apk add --no-cache \
     python3 \
     py3-pip \
     py3-scipy \
@@ -31,17 +40,9 @@ RUN apk add --no-cache \
     py3-gevent \
     zlib \
     jpeg \
-    gcc \
-    g++ \
     llvm9 \
-    make \
-    autoconf \
-    automake \
     libtool \
     supervisor \
-    zlib-dev \
-    jpeg-dev \
-    llvm9-dev \
     py3-numpy-dev \
     python3-dev && \
     mkdir -p /app/cache && \
@@ -50,7 +51,7 @@ RUN apk add --no-cache \
     chmod -R o+rw /var/log/supervisor && \
     chmod -R o+rw /var/run && \
     pip install -r requirements.txt && \
-    apk del --no-cache -r gcc g++ make autoconf automake libtool zlib-dev jpeg-dev llvm9-dev
+    apk del --no-cache -r .build
 
 COPY --from=builder /app/we-lang /app/bin/we-lang
 COPY ./bin /app/bin