Blog example cannot be built because KV connection is listening indefinitely

[marvinhagemeister]

Building the blog example is broken because the process is kept open indefinitely so the build task never finishes. Reason for that is that a Deno KV instance is opened and a listener is attached eagerly. This will prevent the process from exiting.

The kv queue is eagerly listened through this call here:

fedify/x/denokv.ts

Line 102 in 6d57d19

this.#kv.listenQueue(handler);

which is ultimately kicked off eagerly in the constructor of the Federation class here: https://github.com/dahlia/fedify/blob/main/federation/middleware.ts#L197

Commenting this out makes the build task finish as expected.

Steps to reproduce

1. Go into the examples blog folder: cd examples/blog
2. Run deno task build -> Process never exists