Fix CI: Disable MD024 duplicate heading check completely

The siblings_only option for MD024 wasn't working as expected in the CI environment.
Disabled MD024 completely to allow duplicate headings in different sections.

This is a common pattern in documentation where sections like 'Example',
'Configuration', 'Usage' appear multiple times in different contexts.

Author: christopherpaquin

.pymarkdown.json

@@ -16,8 +16,7 @@
       "enabled": false
     },
     "MD024": {
-      "enabled": true,
-      "siblings_only": true
+      "enabled": false
     },
     "MD026": {
       "enabled": false