Add seeder.xchseeder.com to dns_servers in config.yaml (#19125)

I am now running a seeder for Chia at `seeder.xchseeder.com`.  Full details are at [https://xchseeder.com](https://xchseeder.com).

### Purpose:
Add a new seeder into the options of seeder for the config.yaml file. The seeder is at `seeder.xchseeder.com` and was setup and is run by me. It does support both IPv4 and IPv6. I do have some monitors setup on Uptime Robot to ensure it stays healthy and provides a status page for the service. I do have a landing page at `xchseeder.com`.

### Current Behavior:
n/a

### New Behavior:
Another seeder option in the `config.yaml` file.

### Testing Notes:

chia/util/initial-config.yaml

@@ -440,6 +440,7 @@ full_node:
     - "seeder.dexie.space"
     - "chia.hoffmang.com"
     - "seeder.xchpool.org"
+    - "seeder.xchseeder.com"
   introducer_peer:
     host: introducer.chia.net # Chia AWS introducer IPv4/IPv6
     port: 8444