tests: the shipped-Lua archive-path floor follows the census to 3

BENILLA_FALLBACK_ICON held the fourth archive path the sweep counts, and
it is gone. The floor exists so the sweep never passes by matching
nothing, and it comes down as paths leave.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

crates/benilla-app/src/ui_script/shipped_xml_tests.rs

@@ -534,10 +534,10 @@ fn every_archive_path_a_shipped_lua_chunk_names_survives_its_own_escaping() {
             }
         }
     }
-    // Never let the sweep pass by matching nothing (19 after 1971, 8 after 1980, 4 after 1987;
-    // the floor follows the census down as windows migrate).
+    // Never let the sweep pass by matching nothing; the floor follows the census down as windows
+    // migrate.
     assert!(
-        paths.len() >= 4,
+        paths.len() >= 3,
         "only {} archive paths swept out of the shipped Lua",
         paths.len()
     );