refactor(skills): remove obsolete testing aliases (#105363)

src/skills/discovery/chat-commands.ts

@@ -140,4 +140,3 @@ export function listSkillCommandsForAgents(params: {
 export const testing = {
   dedupeBySkillName,
 };
-export { testing as __testing };

src/skills/lifecycle/install.ts

@@ -828,4 +828,3 @@ export const testing = {
     };
   },
 };
-export { testing as __testing };