fix(api): align Swagger schemas for UserSettings and TopicListResponse (#38590)

Corrects the Swagger/OpenAPI schemas for `/user/settings` and
`/topics/search` to match the actual JSON objects returned by the API.

Signed-off-by: Sudhanshu Singh <sudhanshuwriterblc@gmail.com>

routers/api/v1/repo/topic.go

@@ -300,7 +300,7 @@ func TopicSearch(ctx *context.APIContext) {
 	}
 
 	ctx.SetTotalCountHeader(total)
-	ctx.JSON(http.StatusOK, map[string]any{
-		"topics": topicResponses,
+	ctx.JSON(http.StatusOK, api.TopicListResponse{
+		Topics: topicResponses,
 	})
 }