Related to 4.2 no further versions of MongoDB will be built for the following operating system / CPU arch combinations. Some of these have already been removed, the rest will be removed soon:
remove Ubuntu 14 x86_64
remove Debian 8 x86_64
switch Ubuntu 16 arm to ubuntu1804 arm for MongoDB 4.2+
remove generic linux builds for x86_64
If you're using any of these combinations to test in Evergreen you'll have to make changes.