bug(log): warn() and others behave different depending on import

[iuioiua]

Executing warn(), if imported from @std/log, prints to the console. However, when imported from @std/log/warn, it doesn't print anything. I think this is because setup() is executed, as it's included in @std/log, but not executed as it's excluded from @std/log/warn. I believe the fix is to add import "@std/log/setup" to warn() and its sibling functions, like info(), etc.