[Bug]: New gateway becomes default despite `default: false`

[jvstme]

Steps to reproduce

1. Have no gateways in the project.
2. Apply this configuration:

type: gateway
name: test-gateway
backend: aws
region: eu-west-1
domain: example.com
default: false

Actual behaviour

The new gateway becomes default despite default: false.

⠇ Provisioning test-gateway...
 NAME          BACKEND  HOSTNAME  DOMAIN       DEFAULT  STATUS     CREATED 
 test-gateway  aws                example.com  ✓        submitted  now     

Expected behaviour

The new gateway does not become default.

dstack version

0.21.0

Server logs

Additional information

No response