Remove asserts the types already cover

The nil check burn down added guards which turned out redundant once
the surrounding annotations landed. `_has_handlers` is set to true when
the first handler registers, so it is a boolean rather than the literal
false it was inferred as.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

exp_scenario/module/commands/search.lua

@@ -91,7 +91,7 @@ local function sort_results(results, func)
         end
     end
 
-    return sorted
+    return sorted --[[@as SearchResult[] ]]
 end
 
 local display_players_time_format = ExpUtil.format_time_factory_locale{ format = "short", hours = true, minutes = true }