spa-test breaks in Vite 4 due to hydration (data-hk)

[birkskyum]

Part of #660

In spa-test, the combination of 'with index.html' and app.goto('/about') leads to this data-hk inconsistency in Vite 4:

[ryansolid]

Hmm.. that suggests it is getting the server rendered code instead of client rendered. Some configuration issue only present in Vite 4. Maybe the way some setting is merged? Hmm..

I wonder if this is related to the dev mode issue. Some people are reporting their prod builds are getting dev code with Vite 4. Our dev setup might not be handling CSR mode right and this is exposing it. To be clear this test should pass regardless and there is an issue in how the config is being handled.

[birkskyum]

Is there an issue made for the dev mode issue anywhere? Where are these reports?

The prod/dev issue might be a result of this breaking change in vite 4 where the way to set prod/dev flags was being reworked: vitejs/vite#10996