fix: ensure compatibility with vite v6.0.7

[ocavue]

After updating vite from v6.0.6 to v6.0.7, vite-plugin-top-level-await doesn't work anymore. This is because vite-plugin-top-level-await mutates config in the configResolved() hook. This mutation should be done in the config() hook. See the explanation here for more details.

Closes #61

[bayasdev]

+1

[Menci]

Is the target option available (if the user didn't set it explicitly) in the config() hook? I previously used the configResolved() hook to ensure the target option is available.

[ocavue]

@Menci Thanks for pointing out. If user doesn't set if explicitly, target is undefined. I set it as the default Vite target in this case.

[DominicGBauer]

@Menci please can you look at this when you have a chance 🙏 , it's breaking builds for some of our clients.