Error: The action 'lint mathlib' has timed out after 30 minu

Stream: PR reviews

[Yuval Filmus]

CI #261969 gives the following error in the lint mathlib step:

Error: The action 'lint mathlib' has timed out after 30 minutes.

This also happened in a few other attempts.
Is this an actual error or just a bug?

[Moritz Doll]

see https://leanprover.zulipchat.com/#narrow/channel/287929-mathlib4/topic/slow.20linting.20step.20CI.3F/with/568140583