feat(config): add pool_domain and upgrade dependencies

- Add configurable pool_domain with pool.ntp.org default
- Update Go from 1.23.5 to 1.24.0
- Update golang.org/x/* dependencies
- Add enumer and accessory as tool dependencies
- Update goreleaser to v2.12.3

config/config_accessor.go

@@ -23,13 +23,6 @@ func (c *Config) WebHostname() string {
 	return c.webHostname
 }
 
-func (c *Config) PoolDomain() string {
-	if c == nil {
-		return ""
-	}
-	return c.poolDomain
-}
-
 func (c *Config) Valid() bool {
 	if c == nil {
 		return false