fix(hmr): compile files in /node_modules/ with hmr: false

[dominikg]

this saves some time and space, but also ensures consistency in cssHash which avoids bugs like sveltejs/svelte#12601

[Conduitry]

Hm. Could someone conceivably have an npm linked dependency here that they still want HMR for?

[dominikg]

Hm. Could someone conceivably have an npm linked dependency here that they still want HMR for?

for that they would have to add the dep to optimizeDeps.exclude or it would be prebundled which prevents hmr too. but for comparability i'll post a different fix that updates cssHash instead.

[dominikg]

losing in favor of #950