Update CI to cover MongoDB Server 5.0.

MongoDB has alpha releases in a slightly different location on their distribution server. And they use different keys for signing these alpha releases compared to the overall package listing.

Closes #3696
Original pull request: #3753.

ci/openjdk8-mongodb-5.0/Dockerfile

@@ -0,0 +1,17 @@
+FROM adoptopenjdk/openjdk8:latest
+
+ENV TZ=Etc/UTC
+ENV DEBIAN_FRONTEND=noninteractive
+
+RUN set -eux; \
+	apt-get update && apt-get install -y apt-transport-https apt-utils gnupg2 wget ; \
+	# MongoDB 5.0 release signing key
+	apt-key adv --keyserver hkps://keyserver.ubuntu.com:443 --recv B00A0BD1E2C63C11 ; \
+	# Needed when MongoDB creates a 5.0 folder.
+	echo "deb [ arch=amd64 ] https://repo.mongodb.org/apt/ubuntu bionic/mongodb-org/5.0 multiverse" | tee /etc/apt/sources.list.d/mongodb-org-5.0.list; \
+	echo ${TZ} > /etc/timezone;
+
+RUN apt-get update; \
+	apt-get install -y mongodb-org=5.0.0 mongodb-org-server=5.0.0 mongodb-org-shell=5.0.0 mongodb-org-mongos=5.0.0 mongodb-org-tools=5.0.0; \
+	apt-get clean; \
+	rm -rf /var/lib/apt/lists/*;