Don't disable TS extension in debug launch task

[jakebailey]

Now that the main extension handles this gracefully, I think we should stop force disabling it in our launch options, instead allowing things to proceed but warning if tsgo is disabled for some reason. This should make it less annoying to test things that use VS Code settings defined in the main extension.

If the main extension is disabled, then debugging will force tsgo, to at last continue supporting old launch configs. But, maybe that's overkill (but we would need to make everyone re-copy their launch configs.)