We seem to be sometimes seeing an effect of rate-limiting on building Docker containers for package tests, as can be seen here:

https://evergreen.mongodb.com/task_log_raw/mongodb_mongo_master_nightly_debian11_test_packages_patch_fff51c4b07573c2d27ebccdd4bbe2c722fb7b45e_63459dda9ccd4e753acec7b1_22_10_11_16_46_36/0?type=T&text=true

The debian:11-slim image definitely exists. The error appears to be from the perspective of the docker Python SDK client connecting to the daemon on localhost, so it's probably not able to pull the debian:11-slim image from Docker hub. We probably need to log in with our corporate credentials before building these containers so we're not subject to rate-limiting.