chore(docs): Update testcode path (#8923)

Update testcode path

testdata/README.md

@@ -4,9 +4,9 @@ A test suite that tests different aspects of Foundry.
 
 ### Structure
 
--   [`core`](core): Tests for fundamental aspects of Foundry
--   [`logs`](logs): Tests for Foundry logging capabilities
--   [`cheats`](cheats): Tests for Foundry cheatcodes
--   [`fuzz`](fuzz): Tests for the Foundry fuzzer
--   [`trace`](trace): Tests for the Foundry tracer
--   [`fork`](fork): Tests for Foundry forking capabilities
+-   [`core`](default/core): Tests for fundamental aspects of Foundry
+-   [`logs`](default/logs): Tests for Foundry logging capabilities
+-   [`cheats`](default/cheats): Tests for Foundry cheatcodes
+-   [`fuzz`](default/fuzz): Tests for the Foundry fuzzer
+-   [`trace`](default/trace): Tests for the Foundry tracer
+-   [`fork`](default/fork): Tests for Foundry forking capabilities