update: use rfc source.

Author: ya7010

registries/_format/date-time-local.md

@@ -4,8 +4,8 @@ issue: 4759
 description: RFC3339 date-time without the timezone component
 base_type: string
 layout: default
-source_label: TOML
-source: https://toml.io/en/v1.0.0#local-date-time
+source_label: RFC 3339
+source: https://datatracker.ietf.org/doc/html/rfc3339#section-5.6
 ---
 
 {% capture summary %}

registries/_format/time-local.md

@@ -4,8 +4,8 @@ issue: 4759
 description: RFC3339 time without the timezone component
 base_type: string
 layout: default
-source_label: TOML
-source: https://toml.io/en/v1.0.0#local-time
+source_label: RFC 3339
+source: https://datatracker.ietf.org/doc/html/rfc3339#section-5.6
 ---
 
 {% capture summary %}