chore(ci): :green_heart: use standard python for nginx-proxy-tester

test/requirements/Dockerfile-nginx-proxy-tester

@@ -1,7 +1,4 @@
-FROM python:3.9-alpine
-
-# Note: we're using alpine because it has openssl 1.0.2, which we need for testing
-RUN apk add --update bash openssl curl && rm -rf /var/cache/apk/*
+FROM python:3.9
 
 COPY python-requirements.txt /requirements.txt
 RUN pip install -r /requirements.txt