When using an Xcode Step with automatic provisioning, you receive the following error:
error: Choose a certificate to revoke. Your account has reached the maximum number of certificates. To create a new one, you must choose a certificate to revoke.
You can fix this issue by revoking unused certificates and starting the build again.
The possible root cause of this issue
You may encounter this issue because you don't have an uploaded development signing certificate. Steps with automatic provisioning options generate one on the fly every time you start a build. This can eventually lead to reaching the maximum number of certificates, blocking you from starting new builds.
If you are using Steps with automatic provisioning options and don't have an uploaded development signing certificate: