Duplicated extra_output in kontrol init --skip-forge

[palinatolmach]

We're adding extra_output = ['storageLayout'] to foundry.toml on kontrol init without checking if it was present. If it's already present in foundry.toml, it might lead to the following issue:

Error: 
failed to extract foundry config:
foundry.toml error: TOML parse error at line 15, column 1
   |
15 | extra_output = ['storageLayout']
   | ^
duplicate key `extra_output` in table `profile.default`
 in foundry.toml TOML file