apps: Fix watch-appstream.py error handling

cockpit.spawn() never fails with a bare "closed". There are no expected
failures there, so just always warn about them.

pkg/apps/appstream.js

@@ -50,11 +50,7 @@ export function get_metainfo_db() {
                         debug("read metainfo_db:", metainfo_db);
                     }
                 })
-                .fail(function (error) {
-                    if (error != "closed") {
-                        console.warn(error);
-                    }
-                });
+                .catch(error => console.warn("watch-appstream.py failed:", error));
     }
 
     return metainfo_db;

test/common/typecheck

@@ -98,7 +98,6 @@ javascript_ignored_codes = [
     "TS2551",   # Property 'X' does not exist on type
     "TS2304",   # Cannot find name 'X'
     "TS2305",   # Module '"./machines/machines"' has no exported member 'get_init_superuser_for_options'.
-    "TS2367",   # This comparison appears to be unintentional because the types 'Error' and 'string' have no overlap.
     "TS2538",   # Type 'null' cannot be used as an index type.
     "TS2559",   # Type 'never[]' has no properties in common with type 'DBusCallOptions'.
     "TS2769",   # No overload matches this call.