If I have an instance of ZIO Runtime, how do I apply ZLayers (such as the new enableAutoBlockingExecutor in ZIO 2.1) to it to get a modified Runtime?

I see that Runtime has a withEnvironment method, but I am not sure how to create a ZEnvironment from ZLayers.

(My application doesn’t extend ZIOAppDefault, so I don’t have a bootstrap method, or use ZLayers anywhere else. In parts of the system that use ZIO, effects are run manually where needed using runtime.unsafe.run from the Runtime I am attempting to construct.)