Investigate stochastic container build CI failure

[SamuelBrand1]

          > Last push gave error

Error: buildx failed with: ERROR: failed to solve: cfaprdbatchcr.azurecr.io/pyrenew-hew-dependencies:137-unify-argument-pattern-in-pipelines: failed to resolve source metadata for cfaprdbatchcr.azurecr.io/pyrenew-hew-dependencies:137-unify-argument-pattern-in-pipelines: failed to authorize: failed to fetch anonymous token: unexpected status from GET request to cfaprdbatchcr.azurecr.io/oauth2/token?scope=repository%3Apyrenew-hew-dependencies%3Apull&service=cfaprdbatchcr.azurecr.io: 401 Unauthorized

This seems unconnected to last commit (which fixed an error).

After some inconsequential changes to trigger CI this resolved.

@gvegayon should we expect stochastic failure in the container build CI?

Originally posted by @SamuelBrand1 in #138 (comment)

Observed here, but I didn't identify the cause of the failure.