Use Debian Slim Bullseye as the Docker image's base

Dockerfile

@@ -1,18 +1,13 @@
-FROM python:3.7-alpine as build
+FROM python:3.7-slim-bullseye as build
 WORKDIR /wheels
-RUN apk add --no-cache \
-    g++ \
-    gcc \
-    git \
-    libxml2 \
-    libxml2-dev \
-    libxslt-dev \
-    linux-headers
+
+RUN apt-get update && apt-get install -y build-essential
+
 COPY requirements.txt /opt/sherlock/
 RUN pip3 wheel -r /opt/sherlock/requirements.txt
 
 
-FROM python:3.7-alpine
+FROM python:3.7-slim-bullseye
 WORKDIR /opt/sherlock
 ARG VCS_REF
 ARG VCS_URL="https://github.com/sherlock-project/sherlock"