Update MongoDB.

And the repo key URL.

Dockerfile

@@ -11,7 +11,7 @@ RUN apt-get update && \
     mkdir --mode=0700 "$GNUPGHOME" && \
     curl https://packages.cloud.google.com/apt/doc/apt-key.gpg > \
     /usr/share/keyrings/google-cloud.gpg && \
-    curl https://www.mongodb.org/static/pgp/server-4.4.asc | \
+    curl https://pgp.mongodb.com/server-5.0.asc | \
     gpg --no-default-keyring --import --batch --keyring /usr/share/keyrings/mongodb.gpg && \
     curl https://cli-assets.heroku.com/apt/release.key | \
     gpg --no-default-keyring --import --batch --keyring /usr/share/keyrings/heroku.gpg && \

sources.d/mongodb.sources

 Types: deb
 URIs: https://repo.mongodb.org/apt/debian
-Suites: buster/mongodb-org/4.4
+Suites: buster/mongodb-org/5.0
 Components: main
 Signed-By: /usr/share/keyrings/mongodb.gpg