Update Dockerfile to point apt sources to the Debian archive due to Buster EOL, and disable Release file validity checks for successful updates and installations.

Author: bbodine1

.docker/production/Dockerfile.gha

@@ -15,7 +15,13 @@ ENV BUNDLER_VERSION=$BUNDLER_VERSION
 
 # Only install what's needed that isn't in the base image
 # https://github.com/docker-library/ruby/blob/master/2.7/slim-buster/Dockerfile
-RUN apt-get update \
+# Buster is EOL; point apt sources to the Debian archive and disable
+# Release file validity checks so updates/installations work.
+RUN sed -i \
+      -e 's|deb.debian.org/debian|archive.debian.org/debian|g' \
+      -e 's|security.debian.org/debian-security|archive.debian.org/debian-security|g' \
+      /etc/apt/sources.list \
+    && apt-get -o Acquire::Check-Valid-Until=false update \
     && apt-get -yq dist-upgrade \
     && apt-get install -y \
       fontconfig \