Merge pull request #25904 from dvdksn/codex/ai-governance-codeowner

docs: assign AI governance code owner

Author: dvdksn

.github/CODEOWNERS

@@ -37,6 +37,8 @@
 
 /content/manuals/ai/ @dvdksn
 
+/content/manuals/ai/sandboxes/governance/ @craig-osterhout
+
 /_vendor @dvdksn
 
 /content/manuals/offload/ @craig-osterhout