Update to Vite v6

[zoton2]

While updating the bundle to v3 I noticed Vite v6 was released somewhat recently. IIRC the only thing holding me back is vite-plugin-nodecg maybe needing updating.

[zoton2]

Coincidentally this was also brought up by someone else (nodecg/vite-plugin-nodecg#16) and it was suggested no changes were probably needed and that we should just force Vite v6 and test it, which is what I will be doing myself.