Revert "fix(build): temporarily source rust from alpine edge"

This reverts commit 0b068c5.

Author: ChandonPierre

Dockerfile

@@ -21,8 +21,6 @@ ARG DO_DEBUG_BUILD="${DEBUG_IMAGE:-"0"}"
 # Build mitmproxy via pip. This is heavy, takes minutes do build and creates a 90mb+ layer. Oh well.
 RUN [[ "a$DO_DEBUG_BUILD" == "a1" ]] && { echo "Debug build ENABLED." \
  && apk add --no-cache --update su-exec cargo bsd-compat-headers git g++ libffi libffi-dev libstdc++ openssl-dev python3 python3-dev py3-pip py3-wheel py3-six py3-idna py3-certifi py3-setuptools \
- && sed -i 's|v3\.\d*|edge|' /etc/apk/repositories \
- && apk --no-cache upgrade rust \
  && rm /usr/lib/python3.*/EXTERNALLY-MANAGED \
  && LDFLAGS=-L/lib pip install MarkupSafe mitmproxy \
  && apk del --purge git g++ libffi-dev openssl-dev python3-dev py3-pip py3-wheel \